efforts to bring about a ceasefire in Lebanon,
in the face of grave risks that the conflict could
spread out of control. Does France hold the key to
peace in the Middle East?
France now has the key role, with the US, in achieving a ceasefire agreement through the UN Security Council.
France's big foreign policy idea also faces its toughest test yet: it is that the US has destabilised the Middle East through its mistakes, like the invasion of Iraq, and that France can do better as the champion of an alternative European strategy.
The reputation of French President Jacques Chirac is at stake, too. His dismally low support rating shows signs of improving thanks to recent high-profile French diplomacy.
Mr Chirac may hope to score a dramatic international success before next May, when his long political career is expected to end. Success or failure over Lebanon could spell the difference between glory and shame for him and his Gaullist ideas about shaping the world.
So while the world watches in dismay the latest outbreak of a deep-rooted armed conflict across the Israel-Lebanon border, another long-standing rivalry is being played out from New York to Beirut - the diplomatic
struggle between the US and France.
"An important victory for French diplomacy" is how he described the 1 August agreement by EU foreign ministers to follow the logic of France, calling for an immediate cessation of hostilities.
France insisted there could be no military solution to the crisis - so Israel must stop the shooting, as well as Hezbollah. The French also led European protests at what was called Israel's "disproportionate" military response to Hezbollah's provocation.
But the Americans, backed by Britain, placed top priority on allowing Israel to severely weaken Hezbollah for its own long-term security - by that logic an early ceasefire should not be imposed on Israeli forces before that goal is achieved.
The circumstances of this crisis uniquely favour a central role for France:
France is the former colonial power in Lebanon, and a self-styled "friend of the Arab world"; it is the only Western power to have cultivated close links with Arab governments of all kinds, including the former regime of Saddam Hussein in Iraq
- America is politically weakened: militarily stretched in Iraq, and widely seen as having lost the moral authority needed to dictate events
- Britain, the other ex-great power in the region, is seen in the Arab world as compromised by its closeness to the US. It has declined to send troops to a multinational force for Lebanon, leaving France as first choice to lead it.
This could just be a French win-win situation. Their Lebanon diplomacy is helping to mend bruised relations with the Americans.
But Mr Douste-Blazy has also openly fuelled the impression that his country is seeking to fulfil an old ambition - to replace US dominance in global affairs with a European alternative led by France.
He hailed recent events as proof that "a political Europe exists", and that we live in a "multipolar world" - a phrase much used by President Chirac to challenge American authority in 2003 over the invasion of Iraq.
The active French stance enjoys wide support in the European Union. Many leaders are frustrated or angry about what they see as America's culpable failure to advance the peace process between Israelis and Palestinians - the key element needed for the region's long-term stability.
Most Arab states would also welcome a bigger European say in the region's affairs.
Europe has also offered - yet again - to help rebuild Lebanon once the violence is over.
Informally, it is said that France might provide 5,000 troops for a multinational force of around 15,000 in southern Lebanon.
Yet France must also weigh up the acute military and diplomatic risks in taking on the lead role in any outside effort to sort out the Lebanon crisis on the ground:
- Peacekeeping: whatever UN resolutions may say about a ceasefire binding on Israel and Hezbollah forces, any peacekeeping mission in Lebanon will be dangerous. France lost 58 marines killed in a suicide bombing in Beirut in 1983, during an earlier attempt to impose order; the US suffered 241 deaths on the same day
Like France, other nations including Turkey, Norway and Italy say any commitment to send troops to Lebanon would be conditional on satisfactory terms. Germany, the largest EU state, has ruled itself out because of other commitments and sensitivities towards Israel related to the Nazi-era Holocaust
- The French homeland: Mr Chirac says he fears angry Muslim passions over the Middle East may be imported into France itself; that risk would grow if France leads a controversial peacekeeping mission in Lebanon.
Syria: France's traditionally strong ties with Damascus may be useless, after the two nations fell out over Syria's alleged role in last year's assassination of former Lebanese Prime Minister Rafik Hariri and the forced withdrawal of Syrian troops from Lebanon. Yet without Syrian consent no long-term settlement will be secure
Iranian contradictions: France is committed, with the EU and US, to a tough stance towards Iran over its nuclear programme. Yet Iran, as Hezbollah's other main backer, has the power to wreck any agreement and to threaten Israel. The contradiction was plain when the French foreign minister met his Iranian counterpart in Beirut and lauded Iran as a "stabilising force" in the region
France has won general praise for being willing to lead efforts to bring peace to Lebanon. But the hardest part still lies ahead.