That’s not a knock on the President. Since the financial crisis of 2008, the country has been focussed on domestic-policy issues, in which the White House, naturally, takes the lead: the economy, financial regulation, health care, gay marriage, the environment. On the principal foreign-policy issues that animated Obama’s Presidential campaign—ending the wars in Iraq and Afghanistan—he has made sure that his agenda has been followed, sometimes to the frustration of senior officials, such as former Secretary of Defense Bob Gates.

As Gates’s recent memoir makes clear, the White House national-security apparatus kept him and Secretary of State Hillary Clinton on a pretty tight leash. But thanks to a unique constellation of circumstances Kerry has emerged with the opportunity, and the authority, to make a more distinctive mark on history. For the lanky New England prepster, who was previously known principally for his anti-Vietnam War activities and his ill-starred 2004 Presidential campaign, it is quite a turnaround—and one that few envisaged when he succeeded Clinton, last February.

Each of the three challenges Kerry faces is formidable, and he may end up failing at all of them. But even if he does it’s a huge story. Arguably, the consequences of failure would be even greater than the consequences of success: a U.S.-Israeli military strike on Iran’s nuclear facilities, a Sunni-Shiite conflict spreading out from Syria to the rest of the Middle East, and an increasingly isolated Israel intent on going it alone, quite possibly in the face of a third intifada. That would be quite a legacy.

For now, at least, there’s a bit of hope. Last week’s peace talks on Syria, which took place in Geneva, didn’t achieve much. But, as Lakhdar Brahimi, the United Nations mediator, pointed out, the very fact that the two sides sat down together without walking out represented progress of a sort. The interim agreement on freezing Iran’s nuclear program has opened the way for more substantive talks on preventing Tehran from acquiring nuclear bombs. In Israel, Benjamin Netanyahu is facing increasingly loud demands from some members of his right-wing coalition to reject Kerry’s peace plan before it is even unveiled. So far, though, Netanyahu, despite criticizing some of Kerry’s comments over the weekend, has declined to take that step.

The three sets of discussions are separate, of course. And each comes with its own tortuous complications. Still, there are some commonalities that explain why Kerry finds himself with some freedom to maneuver.

One factor playing in his favor is the sheer awfulness of the Sunni-Shiite conflict. If the violence in Syria and western Iraq continues unabated, bringing with it a growing number of hardened jihadist fighters animated by extreme ideologies and willing to export the conflict elsewhere, it could eventually threaten regimes throughout North Africa and the Middle East. Such a prospect tends to concentrate minds. Although regional powers like Turkey and Saudi Arabia have supported the Sunni insurgents who are fighting Assad and his Iranian backers, they have no interest in seeing the entire region turned into a sectarian battlefield. If some face-saving settlement could be found in Syria, they might be willing to support it.

Another thing going for Kerry is the good working relationship that he has forged with his opposite number in Russia, Sergei Lavrov. It goes back to the Syrian chemical-weapons deal that the pair of them improvised last summer, which enabled President Obama to save face. Since then, they have worked closely together to set up the Syria peace talks in Geneva, even larking around on occasion. (At a meeting in Paris a couple of weeks ago, which was a precursor to the talks, Kerry presented Lavrov with two large Idaho potatoes, which the Russian foreign minister described as “impressive.”)

Russia is not only a friend and supplier of arms to Syria’s President, Bashar al-Assad; it is one of Iran’s allies and trading partners, and a member of the P5-plus-1 group that reached the interim agreement with Tehran, last November. As the talks on a permanent settlement get going later this month, the Russians will play an important role. Vladimir Putin, the Russian President, has suggested several times that a possible solution to the crisis would be for Russia, or another country, to refine the uranium that Iran says it needs for power generation. Iran insists on retaining some refining capacity of its own. But, in any case, Lavrov, who visited with Hassan Rouhani, the Iranian President, in December, will be a key player.

Rouhani’s very presence is, of course, another reason why Kerry’s hopes aren’t completely forlorn. Until Rouhani’s election, last June, it appeared silly to think of the United States and Iran reaching any sort of rapprochement. Now the feasible set may be expanding. At the least, it is surely in the West’s interest to encourage moderates in Tehran and to see how far they can bring the mullahs and the Revolutionary Guards. Even some of the U.S. senators who were threatening to bollix things up by introducing new sanctions against Iran appear to be coming around to this view. (In a letter released over the weekend, Hillary Clinton also urged the Senate to “give diplomacy a chance to succeed.”)

On Syria and Iran, there is a general agreement that if things aren’t resolved soon they will only get worse. That also applies to Israel-Palestine, where Israel’s settlement policies are threatening to undermine the viability of an independent Palestinian state on the West Bank, even as a single-state solution, or a permanent occupation, are equally hard to imagine. Kerry, who has yet to reveal the land-for-peace map that he is widely assumed to be carrying in his back pocket, faces enormous obstacles. But his biggest advantage, perhaps his only advantage, is that all sides know this may well be the last chance for a peaceful settlement.

For now, and probably for much of this year, Kerry has the stage. The President’s advisers, ever zealous to promote their boss, are well aware that foreign policy now represents his Administration’s best chance of achieving something historic in his second term to rival universal health care; they also know that failure is the most likely outcome. The logical strategy is to let Kerry make the running. If he overcomes the odds, the President can get involved later on, close the deal, and share the credit. If the Secretary of State comes to grief, the White House can always say Kerry tried his best.

Over to you, John.