"But isn't it extraordinary?" persisted the journalist, in pursuit of the quote of the night. Mr Solana paused, and smoothly rolled out his famed talent for prudence. He said, in English: "Some things are extraordinary and some are ordinary. You will have to qualify this as you wish."
Mr Solana is the only survivor to have lasted the full 13 yearsof Felipe Gonzalez's Socialist cabinet. He has changed ministries several times, moving from culture to education to foreign affairs, in each case establishing a creditable record and, characteristically, making no enemies.
"Conciliatory" and "affable" are words often used to describe a man who is surprisingly informal and relaxed in this most formal of political societies. He moves and speaks amid the splendour of a foreign ministry built to rule a vast and cruel empire with the ease of someone padding about his own front room. Even after 13 years in government, he still talks like a human being, chopping and swallowing his words in his desire to communicate, and it is often difficult to get him to stop.
His full name is Javier Solana Madariaga - the Madariagas being one of Spain's most distinguished intellectual families. A great uncle, Salvador de Madariaga, argued for European integration before the Second World War. But the biggest influence was his father, a chemistry teacher whose career was frustrated by the Civil War, and the atmosphere at home was, Solana says, "extremely liberal". Born on 14 July 1942, the future physicist conducted his first experiments in the family kitchen, heating salt and watching the colours of the flame. Today's Nato supremo, when a chirpy myopic schoolboy, tested his father: why did the wind blow? Why did it rain? And his father explained everything, including why there were injustices in the country. "And so," Solana said once, "I became a physicist and a socialist."
A decisive moment was when his elder brother Luis was detained by Franco's police for being a member of the socialist youth. "I was 16 or 17 and it made me realise what repression was like in those days: visiting Carabanchel [prison] on Thursdays and Sundays."
Javier followed Luis into the socialist youth and was expelled from Madrid's Complutense University in 1963 for student activism. Comfortable family circumstances enabled him to go to the Netherlands, then England, and he won a Fulbright scholarship to the United States of America where he obtained his physics doctorate, met and married his wife Concha, and became intoxicated with the spirit of the Sixties. "I experienced 1968 in the States, the Vietnam War, the human rights movement, the death of Martin Luther King, the big marches on the Pentagon, in New York and Washington. All that had a big effect on me," he says.
Offered a teaching post in Solid State Physics at Madrid's new Autonomous University, he returned in 1971 and became leader of the clandestine Socialist Party in Madrid. By the late Seventies, Franco was dead, democracy was flowering and the socialists were heading for power. Solana, MP for Madrid and physics professor, looked the part: tweed jacket, woollen muffler, scruffy beard - hallmark of a generation of Spanish lefties - and his eternal smile.
The centre-right UCD government was about to take Spain into Nato, and the socialists campaigned furiously against membership. Solana was vociferous but as one Socialist (PSOE) member recalls, "we were all anti-Nato then." The party even published a pamphlet called "50 Reasons For Not Joining Nato." Felipe Gonzalez addressed passionate anti-Nato rallies and on a visit to London made his objections clear to the foreign secretary Lord Carrington, later to occupy the post now offered to Mr Solana.
Solana and Gonzalez met when the high-born intellectual extended a comradely hand to the Sevillian country boy newly landed in Madrid. Today, insiders say Solana is one of the few who still enjoys the Prime Minister's full confidence. When Gonzalez briefly quit as leader in 1978 after the party refused to drop its Marxist tag, Solana was gutted. Gonzalez probably feels the same, now that his friend, until Friday his most likely successor, is leaving him.
Solana's energy and optimism are legendary and he is often teased for opening a briefing about some crisis or other with the words: "I have good news for you." He is personally frugal and austere, eating little, dressing unremarkably. When, during a hectic spell this year he moved out of his marital home to sleep in the ministry, no one doubted his assertion that it was purely pressure of work.
Observers pressed to find a flaw in his character say that his passion to conciliate makes it hard to pin down exactly where he stands, beyond his unswerving loyalty to his party and its leader. He is rare among Spanish politicians for having an informed understanding of and liking for the Anglo-Saxon world. He is fond of Americans, and once said that if he had to choose a country of exile it would be England. He will get on famously with his new allies.