In international relations as in personal life, friendships can be ever-changing. America used to love Britain, prompting many a British leader from Margaret Thatcher to David Cameron to talk of their “special relationship”. Germany and the US also sort of loved each other, with Washington clearly viewing Berlin as the serious, go-to European country for any sensible discussion on the global and Eurozone economic crisis.

Now, it’s French President Francois Hollande and Barack Obama getting cosy while the rest of Europe looks on with a mixture of surprise and envy.

Surprise? Well, for a long time, there was no love lost between Paris and Washington. France — along with Germany — refused to join the US-led coalition against Iraq’s Saddam Hussein, prompting outraged US lawmakers to rename “French fries” served in Congress’s cafeteria as “freedom fries”.

As for envy, clearly, every European country wants to be America’s best friend. For all the talk of a new world order, the increasing power of Europe and Russia and the clout of China and other emerging countries, America’s starring role as global leader remains undiminished — not least in European eyes.

Britain is especially jealous of the Franco-American love-in. But Obama has reassured London that both France and Britain have a place in his heart. As he recently told journalists: “I have two daughters, and they are both gorgeous and wonderful, and I would never choose between them.”

The fact is that while they may shout and scream over Edward Snowden’s revelations of US intelligence services’ spying and eavesdropping on EU leaders, including German Chancellor Angela Merkel, and, of course, many Europeans are angry over issues like Guantanamo Bay, extra-judicial renditions of European citizens and drone strikes, in the end European politicians — like many others the world over — want an invitation to the White House.

And that longing for America’s warm embrace has not diminished following the disparaging “F…the EU” dismissal of European policy in Ukraine by Victoria Nuland, the top US diplomat for Europe.

Discord over the Iraq war notwithstanding, Franco-American fascination with each other goes back a long way, reflected in literature, movies and songs.

The latest chapter in the romance has nothing to do with wine or song, however: it’s about war. Specifically, it’s about President Hollande’s unexpectedly activist interventionist policies in Africa — and potentially in the Middle East.

As the rest of Europe, including Germany, deliberates over the ethnic violence in Africa, France has taken the lead in deploying troops in Mali and the Central African Republic (CAR).

True, other European countries have said they will join the French in the CAR — but so far it’s France which is carrying the brunt of military responsibilities.

As Washington seeks to disengage from some of its global burdens and urges Europe to take on a more active peace-making role, France under Hollande seems like the perfect ally.

Increasingly, US policymakers know that they will need Paris in the years ahead in the Middle East but also to fight off Al Qaeda in the Sahel and help boost security in countries from Senegal to Somalia.

Washington also remembers that while Britain backed off at the last minute, France was ready for military strikes against Syria following revelations of the use of chemical weapons last year.

“More nations must step forward and share the burden and costs of leadership,” the French and US presidents wrote in a joint article published in Le Monde and the Washington Post newspapers.

In another sign of surprising rapprochement, Hollande gave his full backing to a controversial US-EU free trade deal, saying the accord would strengthen economic growth on both sides of the Atlantic.

“As soon as principles have been set, as soon as mandates have been given, speed is not a problem, it’s of the essence,” Hollande insisted, adding: “We have everything to gain from going quickly. Otherwise, we know there would be a pileup of fears, of threats, of anxiety.”

Until recently, some of these fears were expressed by France as it sought to protect its cultural heritage — and language — in the face of American cultural power.

On a personal level, the press coverage and hype surrounding the US trip is a boon for Hollande at a when time he is struggling with a worsening economy and unemployment hovering around 11 per cent.

The president’s personal ratings are also low but his complicated love life appears to have endeared him to many French women.

There were no references in Washington to Hollande’s very public recent split with his partner Valérie Trierweiler following his affair with French actress Julie Gayet.

French women’s magazines who once derided their president as uninspiring now see a sophisticated and polished “lady’s man” capable of attracting some of France’s most beautiful women.

President Obama may see Hollande as America’s most reliable ally. But for many French women, it’s their president’s very unreliability that makes him such an attractive partner.

The writer is Dawn’s correspondent in Brussels.