Over the last two months, according to the State Department, Secretary of State John Kerry has spent 31 days traveling to 18 countries. He has spent 123 hours in the air. He has been to Turkey three times. He has met five times with Palestinian President Mahmoud Abbas. Kerry has served, in short, as a one-man diplomatic corps, a first responder to global crises. Meanwhile, the State Department limps along with hardly an assistant secretary in place. You could argue that Kerry has his priorities backwards. But you would be wrong. I say this not because Kerry has succeeded on his lightning dashes around the globe. He's had at least as many reversals as breakthroughs. He (and President Barack Obama) brokered a rapprochement between Israel and Turkey -- but the deal is now threatened by Turkish Prime Minister Recep Tayyip Erdogan's announced plan to visit Gaza. Kerry's hopes of re-starting peace talks between Israel and Palestine hinge in part on directing private investment to Palestine; but he could not prevent Salam Fayyad, the Palestinian prime minister and key international interlocutor, from quitting. All that comes with the territory; you can't succeed or fail after two months in a job like this. But you also can't make progress on any of these frozen crises without making a new start. Middle East peace talks, Israel-Turkey relations, negotiations with Iran -- they've all been more or less in a holding pattern since 2010. On Syria, the Obama administration has adopted a policy of no policy while its worst fears -- a sectarian civil war serving as a magnet for jihadists -- have come to pass; the Syrian regime has now provoked a crisis in the White House by apparently transgressing the President's "red line" on the use of chemical weapons. Iraq, too, is coming apart at the seams, with a Shiite government trying to crush its Sunni opponents. In his angry screed, Dispensable Nation, Vali Nasr charges that Obama has abandoned his own professed faith in diplomacy. But Kerry hasn't; and he is doing his best to renew the administration's depleted energies. The potential danger of Kerry's one-man show is not so much that he'll ignore the home front but that he'll persuade himself that he -- and only he -- can cut the world's Gordian knots, raising expectations he cannot possibly satisfy. This is, after all, the same man who was convinced that he could make Bashar al-Assad a partner for peace. Two years ago, Kerry described Assad to me as "a serious, thoughtful, intelligent guy who has a sense of direction for the country." As chairman of the Senate Foreign Relations Committee, Kerry was working every angle of the Israel-Turkey-Syria relationship, hoping that if he just kept pushing he might help deliver Middle East peace. Indeed, Kerry spent the last four years believing that, with a little more persistence and calculation, a few more quiet back-channel phone calls, someone -- a certain very tall, very earnest, very well-connected someone -- could move the needle on the world's most intractable problems. Now he has the chance to show that he was right, which is why he's burst out of the gate like a half-crazed bronco. Kerry may prove to be wrong; but as a friend of mine used to say, you can't hit if you don't swing. I asked Nicholas Burns, who after serving five secretaries of state, most recently as undersecretary to Condoleezza Rice, may be the foremost authority on the job: Has he watched Kerry's one-man show with any misgivings? The opposite, he said. He compared Kerry to the most successful recent secretaries, including James Baker and George Schultz, who worked the big issues relentlessly, personally, and several levels deep. "There is no substitute for the secretary of state in our system," as Burns put it. In the end, he says, the secretary is "negotiator-in-chief," and has to spend more time personally tending to crises than managing the department and even fighting inter-agency battles. Of course, if Kerry's judgment is seen as wrong, or in any case at odds with that of the president, he's going to lose those inter-agency battles and become irrelevant. See under: Cyrus Vance and Colin Powell. At a White House meeting earlier this month, Antony Blinken, the deputy national security advisor, warned against a conference Kerry was planning with President Hamid Karzai of Afghanistan and Ashfaq Parvez Kayani, Pakistan's military chief. Relations between the two countries had been in a downward spiral for months, with each bitterly accusing the other of sabotaging peace. The White House feared the meeting might make things worse. But Kerry believes, with good reason, that he has better relations with Karzai and Kayani than anyone else in the administration, and thus is uniquely positioned to fashion the exit ramp from the region that Obama is desperately seeking. At a "principals meeting" the following week, Kerry said that he felt that he could nudge the two a little closer together on political reconciliation with the Taliban. The White House signed off. Earlier this week, the three men met in Brussels. Afterwards, only Kerry spoke, offering no hint of a breakthrough. "Frankly," he said, "we all agreed that it's better for our populations to have a sense that we're going to under-promise but deliver." That sounded like papering-over-disagreement language, in which case it would appear that Kerry had gone to the mat with the White House, only to fail. But three administration officials told me that in fact the meeting had gone well, and perhaps better than expected. Kerry had promised the White House that he would be careful to manage expectations; the goal was to restore relations between the two countries more or less to where they had been at the end of last year, when Pakistan had made some modest gestures towards supporting political talks with the Taliban. And that's more or less what Kayani promised to do in Brussels. In turn, Karzai may have pledged to tone down his truculently anti-Pakistani rhetoric. Kerry has, in fact, been here before. Since 2009, he has talked Karzai and Kayani off a series of ledges, only to see them climb back up once he's left town. The fact that he's now secretary of state adds weight to his diplomacy, but it won't change that dynamic. The United States, Afghanistan, and Pakistan have national security interests which clash in central ways; diplomacy can not change that, though it can help leaders recognize and build on their shared interests. Kerry is genuinely good at that. We'll see how much it matters. We are, in any case, only seeing the uppermost portions of what Kerry is hoping to build. The Israeli newspaper Haaretz recently reported that Kerry has been trying to arrange a Middle East peace summit which would bring Abbas, Israeli Prime Minister Benjamin Netanyahu, and Jordan's King Abdullah to Washington in June, perhaps along with Turkey and leading Arab nations. This would pose a giant risk of raised expectations and monumental disappointment, and it's hard to believe that Obama would sign off without very strong prior commitments from Israel and Palestine, and maybe also Turkey and Saudi Arabia. That's a lot of moving parts, and you can be sure that Kerry has been working the issue furiously. I have written in the past that Kerry is a man of physical courage and intellectual caution. I have no reason to change that view. But now that he is secretary of state, what matters is whether he has what I would call diplomatic courage: the willingness to throw yourself into a negotiation whose outcome you know that you cannot control, and which may well end badly. Of course one also needs prudence, judgment, patience, and hard work; but we already know Kerry has that. Now we know as well that he is prepared to take risks, to err on the side of trying. If Obama can bring himself to trust him, Kerry just might accomplish big things.