In What Some Call an Unlikely Choice, Spaniard Picked to Lead NATO : Alliance: Socialist Javier Solana, whose party opposed U.S. bases in his country, is chosen to succeed Willy Claes.

Ending a long, troubled search, NATO selected Spanish Foreign Minister Javier Solana on Friday as its next secretary general.

“The ambassadors have agreed by consensus to propose . . . Mr. Javier Solana as secretary general of NATO and chairman of the North Atlantic Council,” said a statement issued by the North Atlantic Treaty Organization’s 16 ambassadors after an informal meeting.

The 53-year-old Spaniard is expected to be formally appointed Tuesday at a scheduled meeting here of NATO foreign ministers.

Although he has come to be respected as a skilled diplomat with a special knack for consensus-building during his 3 1/2 years as foreign minister, Solana is in many ways an unlikely choice to head the world’s most powerful alliance.

His background is academic (solid-state physics), and his Spanish Socialist Workers’ Party actively campaigned against the stationing of U.S. F-16 fighter jets on Spanish soil and pushed for the closure of U.S. military bases in Spain during the 1980s.

Spain is also not fully integrated into the alliance’s military arm because it assigns no military forces to NATO during peacetime.

When Solana’s name first began to appear on some unofficial short lists for the job, observers joked that no bearded Socialist would ever be permitted to lead NATO, let alone one from a nation that is short of full military involvement.

But those observers were proved wrong, just as they were wrong three weeks ago when alliance insiders had become convinced that former Dutch Prime Minister Ruud Lubbers had won the job.

“It’s a little bit surprising,” said John Chipman, director of the London-based International Institute of Strategic Studies. “All these things that may have worked against Solana were apparently put aside for someone who has shown fidelity to the transatlantic idea, has obvious diplomatic skills and knows Bosnia.”

With Spain just finishing six-month terms in the presidency of the European Union and Europe’s military grouping, the Western European Union, Solana has been deeply involved in the Balkans crisis, something that is considered a key asset.

His selection Friday came only hours after the alliance ambassadors formally authorized deployment of advance teams to Bosnia to prepare for the most ambitious operation NATO has ever undertaken--leading a combat-ready force of 60,000 troops to implement a Balkans peace settlement.

First elements of the so-called “enabling force” of 2,600 soldiers are now being dispatched to begin such tasks as checking communications, warehousing facilities and securing land routes that have been earmarked for use by the main force when it comes later this month.

While Solana will be confronted immediately by the full weight of the operation in Bosnia-Herzegovina, he also takes over as NATO grapples with other crucial issues that could eventually decide the fate of the alliance over the longer term.

These issues include the challenge of developing a constructive, cooperative relationship with Russia and enlarging NATO membership eastward by taking in nations that once fell under Moscow’s orbit.

“He’ll be at the helm during NATO’s most testing time,” summed up one alliance official. “He can go down as the man who steered the alliance into a new era or as the one who got it all wrong.”

Solana was picked six weeks after Willy Claes was forced to resign after being linked to a scandal in his native Belgium.

The Spaniard’s emergence ends an embarrassing, divisive search that produced a rare public spat between alliance members when the Clinton Administration effectively vetoed Lubbers, the choice of French President Jacques Chirac and British Prime Minister John Major.

Solana is said to have enthusiastic backing from the United States, Canada and European member states.

Secretary of State Warren Christopher praised Solana’s selection.

“I feel confident, knowing him well, that Javier Solana has the skills and the strength and the leadership ability to lead NATO during this very difficult period,” he said.

For many, Spain’s leading diplomatic role in recent months as head of the EU and WEU gave Solana the chance to demonstrate his skills.

Last month at an EU-sponsored meeting in the Spanish city of Barcelona, Solana won praise for his ability to get a large group of diverse nations--including Syria and Israel--to sign a strong final communique on the issue of Mediterranean security and development.

“This whole exercise has given him an exposure to senior levels of the U.S. government and European Union governments that’s clearly elevated his status enormously and proven that he’s a world-class statesman,” said Stuart E. Eizenstat, the U.S. ambassador to the EU.

Solana was born in Madrid, holds a doctorate in physics and was a Fulbright scholar at several universities in the United States. He also taught solid-state physics at Madrid’s Complutense University.

He joined the Spanish Socialist Workers’ Party in the mid-1960s and served as culture minister, education and science minister and chief government spokesman under Prime Minister Felipe Gonzalez before becoming foreign minister in June, 1992. He and Gonzalez are said to be friends.

As the ninth secretary general in NATO’s 46-year history, Solana would be the first Spaniard and only the second from a Mediterranean country in an organization whose focus has traditionally been on Northern Europe.

Times staff writer Art Pine in Washington contributed to this report.