These are only two of the major ironies of an Alliance marking its 50th anniversary on April 4, 1999. The United States long planned to host a celebratory summit in late April to welcome Poland, Hungary, and the Czech Republic into NATO, making them the first new members since the end of the Cold War.

Plans called for NATO leaders to use the occasion to shift the focus of the Alliance to the challenges of the 21st century-combating the spread of weapons of mass destruction, ethnic violence, and regional conflict. The White House hoped that the unveiling of a compelling new vision for NATO will garner public support for continuation of an alliance that critics regard as a costly bureaucratic anachronism.

Once the cornerstone of Western security, NATO today struggles to attract and hold popular allegiance and sufficient resources. Western Europeans are plunging into a variety of international alliances and organizations with Eastern Europe, all designed to deal with the economic, political, and security challenges faced by greater Europe.

Meanwhile, NATO's leaders are struggling to bolster the unique trans-Atlantic security tie between Europe and the US amid competition from the 10-nation Western European Union, deepening economic integration within the 15-nation European Union, and the growing political and security role of the 55-nation Organization for Security and Cooperation in Europe.

In the run-up to the anniversary summit, Secretary of State Madeleine K. Albright vowed that the event would lay out a vision for a "new and better" NATO.

Said Albright, "We want an Alliance strengthened by new members; capable of collective defense; committed to meeting a wide range of threats to our shared interests and values; and acting in partnership with others to ensure stability, freedom, and peace in and for the entire trans-Atlantic area."

In the Beginning

Alliance leaders celebrate the anniversary in an international atmosphere far different from that of the dark, early days of the Cold War, when Allied leaders were searching for ways to deter threatened aggression by the Soviet Union.

With the end of World War II, Americans soon pressed for demobilization. Winston Churchill, Britain's former wartime prime minister, tried to rouse Americans to the emerging danger of Soviet aggression, declaring in Fulton, Mo., on March 5, 1946, "An iron curtain has descended across the continent" of Europe, raising the specter of confrontation between the East-West Allies that defeated Nazism and Fascism.

Soviet­sponsored Communist governments were taking power in Poland, Bulgaria, Romania, Hungary, and Czechoslovakia. Communist forces scored gains in the civil war in Greece. Yugoslavia joined the Communist bloc, and in adjacent Albania, anti-Nazi forces had created a Communist government in 1944. Soviet forces began harassing Allied rail and road traffic into occupied Berlin.

The tide of Soviet expansion rang alarm bells across the war-weary Low Countries of Belgium, Luxembourg, and the Netherlands, as well as Britain and France-nations that had battled invaders from the East in two world wars. These five anxious nations concluded the Brussels Treaty on March 17, 1948, seeking collective defense arrangements.

On July 6, 1948, barely two weeks after Soviet forces blockaded road and rail traffic into Berlin, the US and Canada opened negotiations with the Brussels Treaty Powers to formulate security arrangements. By October 1948, the seven nations had reached "complete agreement on the principle of a defense pact for the North Atlantic," setting the stage for negotiations on a "North Atlantic Treaty" in Washington, D.C., in late 1948.

With the Berlin Airlift in full swing, supported by supply ships sailing from the United States, US officials sought ways to protect the North Atlantic sea lanes that had been so vulnerable to German U-boats in World War II. With an eye on geostrategic choke points that could be used to bottle up Soviet naval forces, leaders of the seven-nation North Atlantic Alliance on March 15, 1949, invited five militarily limited nations to join the effort.

Denmark's geographic position offered potential control of the straits between the Baltic Sea and the open ocean. Iceland and Norway offered possible control over the North Atlantic "gaps" through which Soviet maritime forces in Arctic waters would have to pass in order to reach vital western sea lanes. Italy provided a geographic sentinel in the heart of the Mediterranean. Portugal offered bases to enable Allies to overfly and patrol the Strait of Gibraltar at the mouth of the Mediterranean.

Article 5

Leaders of the 12 Alliance nations, when they signed the Treaty of Washington in that first week of April 1949, committed their countries to Article 5, which affirmed that each ally would treat an attack on one as an attack on all, though without ever mentioning an "enemy" or the Soviet Union.

Already, hundreds of millions of dollars were flowing to Western Europe under the Marshall Plan. Soon, President Harry S. Truman augmented the existing aid with another $900 million of US military assistance to the newly allied nations. The US­dominated Alliance handed over key military command to American generals, naming Gen. Dwight D. Eisenhower the first Supreme Allied Commander Europe on Dec. 19, 1950. The top civilian post of NATO secretary general went to Britain's Lord Ismay, the first of nine Europeans to hold the post.

NATO's evolution hinged on the ebb and flow of the Cold War. The Soviet Union tested its first atomic bomb in August 1949, and then Soviet-backed North Korean forces launched an invasion of South Korea in June 1950. Alarmed by these events, NATO launched a military buildup and forged an integrated military command structure. NATO based its Cold War strategy upon a classified NATO document known as MC 14/3. The plan emphasized deterrence of Soviet attack with forward deployed conventional forces backed by the threat of a potential US nuclear response to any aggression against Western Europe.

Soon, the Allies reached out for control of yet another maritime choke point, inviting Greece and Turkey to join the 12-nation Alliance in October 1951. The new members offered the Allies ports and airfields to control the eastern Mediterranean and the Dardanelles, giving NATO the leverage to bottle up the Soviet Union's Black Sea fleet in the event of conflict. NATO put the entry of Greece and Turkey on a hurry-up timetable, and the two entered the Alliance within five months of the decision.

The Allies moved to bolster the central front, as well. On May 6, 1955, NATO invited the new Federal Republic of Germany to become the 15th nation in NATO. The Kremlin, ever sensitive to deepening integration of West Germany into the West's defensive perimeter, or anything resembling German rearmament, retaliated by creating the Warsaw Pact of East Germany, Poland, Hungary, Czechoslovakia, Romania, Albania, and Bulgaria.

NATO soon confronted limitations. The Alliance was forced to stand by in 1956 when Soviet-backed Polish communist forces crushed anti-regime riots in Poznan, Poland, in June and Soviet forces broke the Hungarian rebellion in November.

The Soviet Union caught the West by surprise, as well, by testing an intercontinental-range ballistic missile in June 1957 and then launching the first orbiting satellite-Sputnik-on Oct. 4, 1957. Sputnik awakened Americans to a new threat from above. The Soviet Union's successful orbiting of Maj. Yuri Gagarin on April 12, 1961, heightened the alarm.

High Tensions

Tensions mounted when Soviet forces downed an American U-2 spy plane over Soviet territory May 1, 1960, capturing Francis Gary Powers. Nikita Khrushchev kept up the pressure, first at his summit with President John F. Kennedy in Vienna in June 1961 and then with East Germany erecting the Berlin Wall on Aug. 13, 1961, to divide a city that had been administered by the four occupying powers since the end of World War II.

NATO stepped forward to establish a mobile task force to reinforce American, French, and British forces in West Berlin if needed. The United States pointedly moved ground forces into West Berlin by road across East German territory.

The Soviet­bloc ventures prompted greater military preparations by NATO. In 1962, NATO planners won greater clout for dealing with any Soviet invasion across the heavily armed central front with the decision by President Kennedy and British Prime Minister Harold Macmillan to commit part of their nations' strategic nuclear forces to NATO.

NATO, on Dec. 14, 1966, established the Nuclear Defense Affairs Committee and the Nuclear Planning Group to coordinate Allied strategic planning for the combat use of nuclear weapons. To buttress the link between the United States and Western Europe, NATO formally adopted the new strategic concept of "flexible response" in December 1967, signaling US readiness to use tactical and theater nuclear weapons based in Europe as weapons of last resort against any Soviet invasion of Western Europe.

France, under President Charles de Gaulle, disputed the policy and what he viewed as France's subservient role in it. He and others viewed it as an attempt to make it safe for the US to fight a limited nuclear war in Europe. France pulled out of NATO's integrated military command structure, though it remained a member of the Alliance.

In the late 1960s, the Allies matched preparations for war with publicly declared readiness to ease East-West tensions. The United States and the Soviet Union opened direct air links in 1966 and joined 60 other nations in 1967 to sign the first international treaty providing for peaceful exploration and use of outer space. In 1967, NATO responded to the slight thaw in the Cold War by adopting the landmark Harmel Report, an act that put promotion of detente on an equal footing with defense and deterrence of Soviet attack.

NATO in 1971 began exploring conventional force reductions with the Soviet Union. The effort contributed to the 1984 Stockholm Conference's accord on Confidence- and Security-Building Measures and Disarmament in Europe, a building block for the Conventional Forces in Europe accord to reduce conventional forces from the Atlantic to the Ural Mountains.

"First Use"

Improving East­West relations moved nuclear arms control to center stage. The Warsaw Pact renounced first use of nuclear weapons in 1976 in an effort to build public support within NATO countries to force abandonment of Alliance doctrine, which left open the option of making first use of nuclear weapons to halt an attack, even an attack with only conventional forces.

NATO rejected the Soviet proposal, citing the Allies' need for nuclear weapons as a defense of last resort in the face of an enormous, numerically superior Warsaw Pact conventional force.

In 1977, NATO's Nuclear Planning Group launched a study of theater nuclear force modernization. The study led to adoption in December 1979 of the so-called dual-track decision. In that decision, NATO pledged to pursue arms control initiatives with the Soviet Union at the same time it was upgrading NATO's arsenal of theater nuclear weapons. The idea, in short, was that Moscow could limit or even forestall the deployment of NATO Euromissiles but only if it drastically curtailed deployments of its own mobile SS-20 missiles.

The Reagan Administration's build-and-negotiate strategy, however, soon encountered European concerns that US actions would ignite Soviet retaliation against Europe. Large-scale protests erupted. In the end, the Alliance held firm; beginning in late 1983, the Euromissiles were deployed in West Germany, Italy, Belgium, and the Netherlands. Soon, though, Moscow was back at the arms control table and this time with a new leader--Mikhail Gorbachev. This time, the negotiations produced an accord-the Intermediate-Range Nuclear Forces Treaty-calling for the elimination of an entire class of nuclear weapons.

However, the Soviet Union had put the Alliance through a nerve-racking crisis in 1983-84, canceling all arms talks with the US and stepping up its own deployment of SS-20s. The result was new divisions between the US and its Allies. Seven European nations reactivated the Western European Union in mid-1984, giving impetus to a loose knit alliance of European members of NATO. By 1987, France and Germany were discussing the formation of a largely symbolic but still important Franco-German brigade. The two nations, combatants in both world wars, formed a joint security council in 1988. Spain and Portugal joined the WEU in 1988.

The Alliance had frequently demonstrated a willingness to accommodate European demands for a bigger voice in the Alliance. NATO had moved its headquarters and rejiggered defense planning, following the decision by French President de Gaulle to withdraw French forces from military integration with NATO. NATO adapted to a decision by Greece to withdraw its forces from the Alliance's integrated military structure in mid-1974 and later welcomed reintegration of Greek forces in 1980. When Spain joined the NATO Alliance May 30, 1982, as the 16th member, NATO accepted Spanish refusal to allow nuclear weapons on its soil.

Soon, the accommodation was happening again. The Alliance began taking steps to reach out to the East: The first concrete step, albeit modest, was the June 18, 1990, award for the first time of 55 one-year fellowships not only to citizens of NATO's 16 nations but also, for study of democratic institutions, to citizens of former Soviet­bloc nations.

The Big Drawdown

At the same time, the United States and NATO initiated dramatic force reductions in Europe. US forces in Europe dropped from 300,000 to 100,000. Two-thirds of the land forces stationed in Germany were withdrawn. Large scale trans-Atlantic reinforcement exercises such as REFORGER were ended. The number of forward based combat aircraft dropped 70 percent, and their readiness eased, too, with barely half NATO's air assets kept at 30 days' readiness or better, compared to nearly 70 percent kept at 12 hours' readiness in 1990.

NATO's embrace of Eastern Europe intensified in July 1990 when NATO leaders concluded the London Declaration--proposing unprecedented East-West day-to-day cooperation with former Warsaw Pact nations. (The Warsaw Pact was formally dissolved in 1991.)

In its 1991 update of its strategic concept, NATO declared, "Risks to Allied security are less likely to result from calculated aggression against the territory of the Allies, but rather from the adverse consequences of instabilities that may arise from the serious economic, social, and political difficulties, including ethnic rivalries and territorial disputes, which are faced by many countries in Central and Eastern Europe."

In a step unimaginable just a few short years before, the Soviet Union itself vanished. Gorbachev announced his resignation as Soviet leader and signed a decree relinquishing his role as supreme commander in chief of Soviet forces on Dec. 25, 1991. The successor to Gorbachev was Boris Yeltsin. Replacing the Soviet Union was the Russian Federation and 14 new nations that had been part of the Soviet structure.

NATO viewed Russia as a potential ally and underscored its view in early 1992 by committing NATO transport aircraft to airlift humanitarian assistance into Moscow and St. Petersburg. Alliance courtship of Russia symbolically deepened all the more when NATO Secretary General Manfred Wörner took part in a high-profile Washington, D.C., conference to map aid to Russia.

Yeltsin visited NATO headquarters Dec. 9, 1993, just three days before Russia carried out the first multiparty parliamentary elections since 1917.

Fast moving developments in early 1994 cemented the post­Cold War architecture that gave NATO a key role in reshaping security across Eastern and Western Europe. President Clinton led NATO Allies at a Brussels summit Jan. 10-11, 1994, to launch the so-called Partnership for Peace program that invited former Warsaw Pact nations and Conference on Security and Cooperation in Europe nations to forge day-to-day working ties with NATO en route to potential membership. The first NATO­PfP peacekeeping exercise was held in September 1994.

By late 1998, 27 nations, including Russia, had signed up. Twelve of the partners, including the three nations that won entry in 1999, expressed interest in joining NATO.

Special Relationship

NATO pressed ahead with its bid to create a special relationship with Russia, forging a treaty between the Alliance and Russia in May 1997 that laid the foundation for the NATO-Russia Permanent Joint Council. NATO also concluded a charter on a "distinctive partnership" with Ukraine. To assuage East bloc concerns, NATO stipulated that the Alliance has "no intention, no plan, and no reason" to deploy or store nuclear weapons on the territory of former Warsaw Pact nations such as Poland, Hungary, and the Czech Republic that are joining NATO. Nor did the Alliance promise to forgo nuclear weapons deployment if necessary in the future.

The end of the Cold War forced the Alliance to shift its focus to the once-taboo "out-of-area" threats. Several NATO Allies contributed forces to the coalition that ousted Iraqi occupation forces from Kuwait in the 43-day Persian Gulf War in early 1991. NATO aircraft from the Allied Command Europe Mobile Force were deployed to southeastern Turkey Jan. 2, 1991. The operation was the first combat use of the small multinational force since its creation in 1960.

NATO signaled concern over ethnic strife in the East as early as Aug. 9, 1989, when Wörner expressed Allied concern over Bulgaria's treatment of ethnic Turks within Bulgaria.

When cease-fire agreements were repeatedly made and broken in Bosnia after civil war erupted in 1991, NATO repeatedly appealed for combatants to respect cease-fire arrangements. But paralyzed by the necessity for consensus and unanimity, NATO was forced to adopt a step-by-step approach in concert with the United Nations that required a cumbersome and time consuming "dual key" decision making process for any military action.

Initial steps were modest. In July 1992, NATO created a maritime operation in the Adriatic Sea to monitor Balkan embargo compliance by Serbia and Montenegro. Within four months, "monitoring" shifted to "enforcement," provided by both NATO and WEU forces. The combined operation became known as Sharp Guard in June 1993. By the time NATO and the WEU had ceased enforcement in 1996, Allied warships had challenged 74,000 ships, inspected nearly 6,000 vessels at sea, and diverted 1,400 vessels to port for inspection.

Moreover, on Oct. 14, 1992, NATO provided AWACS aircraft to "monitor" a UN-declared "no-fly zone" across Bosnia. Three months later, NATO approved Allied "enforcement" of the no-fly zone. By April 1993, NATO warplanes were flying sorties to enforce Operation Deny Flight from both US aircraft carriers and from bases in Italy.

First Actual Combat

The stepped up Alliance efforts over Bosnia led to the first NATO combat operation in its history. On Feb. 28, 1994, NATO aircraft shot down four Serbian warplanes violating the no-fly zone over Bosnia. Over the course of the next 20 months before the US-brokered Dayton Peace Agreement, the United Nations called on NATO forces to carry out combat action at least a dozen times to provide close air support for UN peacekeeping troops, to shoot down aircraft defying the no-fly zone, or to stage airstrikes against UN-selected targets, ranging from single tanks to heavy weapon bunkers to anti-aircraft sites.

Then, in August 1995, a three-week campaign-called Deliberate Force-was launched. It included some artillery fire, but it was dominated by airpower, the weight of which hammered the Bosnian Serb heavy weapons, ammunition depots, command-and-control bunkers, and other targets. At the same time, NATO air forces undertook a parallel operation called Dead Eye, which took down the Serbian Soviet-style air defense network.

Within three weeks of the first bomb on target, recalcitrant Serb leaders agreed to enter serious negotiations with their foes in the three-year-old war. Within two months, the Dayton Peace Agreement had been signed, effectively bringing the war to a halt.

The US-brokered Dayton peace accords changed NATO's role forever. A 60,000-strong US-led NATO Implementation Force entered Bosnia in December 1995 on Operation Joint Endeavor to implement the Dayton peace accord. The operation was the first ground force operation in NATO history, the first out-of-area deployment by NATO forces, and the first joint operation between NATO forces and non-NATO forces.

A year later, on Dec. 20, 1996, the NATO-led IFOR was replaced by a smaller, more mobile and lightly armed 31,000-strong NATO-organized Stabilization Force. Known as Operation Joint Guard, the second force was assigned to deter resumption of hostilities and to provide selective support for civilian reconstruction efforts. NATO troops staged periodic raids to capture suspected war criminals who were dispatched to the Hague for trial by an international war crimes tribunal.

By the end of 1998, NATO had added a new role in the Balkans, providing 1,800 troops in Macedonia to serve as an extraction force for the 2,000 unarmed monitors sent into Kosovo to deter clashes between Yugoslav Serbian military forces and Albanian rebels seeking independence for the predominantly Albanian province within Serbia.

As the 50th anniversary approached, NATO began a more wide-ranging transformation to combat the threats of the post-Cold War era. NATO revamped its military structure, cutting the number of headquarters from 65 to 20. The two strategic commanders--for Europe and for the Atlantic--remained American generals.

Allies mapped plans to turn over NATO forces to the command of combined joint task forces to carry out specific tasks outside the normal role of the NATO Alliance. The task force concept, road tested in the Balkans, offered a diplomatically acceptable route for NATO and Russia to cooperate in the field. NATO agreed to have the deputy SACEUR, always a European, lead any WEU-led combined joint task force operations involving NATO forces.

NATO officials looked for the summit to bolster a trans­Atlantic bond. "To complete Europe's post-Cold War consolidation, we need engagement," Javier Solana, NATO's secretary general, wrote in a year-end article for Time Magazine. However, Solana said, the Alliance will only be successful "if it stands together."