When you’re the US secretary of state, you’ve visited the Middle East five times in less than four months, you can’t get Israelis and Palestinians to so much as sit down together, and yet you’re still claiming success is just around the corner, you must really have confidence in yourself.

“I’m pleased to tell you that we have made real progress on this trip,” the indefatigable John Kerry told some highly dubious reporters on Sunday at a press conference before flying out of Ben Gurion Airport. “And I believe that with a little more work, the start of final-status negotiations could be within reach. We started out with very wide gaps, and we have narrowed those considerably.”

For the last four days, Kerry has talked with Prime Minister Benjamin Netanyahu, Palestinian Authority President Mahmoud Abbas, and their respective teams, in Jerusalem, Ramallah and Amman. And talked. And talked.

His farewell appearance at Ben Gurion, at which Kerry apologized for being unable to detail what exactly “real progress” means, allowed for only one conclusion: Visit number five had ended much like the previous four — with an optimistic-sounding statement attesting that both sides are interested in peace… but not interested enough to meet face to face and discuss how to get it.

The secretary promised, albeit sounding rather more dutiful than enthusiastic, that he’d be back soon. Skeptics — and five breakthrough-free trips have made skeptics of most everyone, bar Kerry — suspect that visit six (and perhaps seven, for that matter, not to mention eight) will end with exactly the same result.

“’There is progress but there are a few things we need to work on’ — that’s how failure sounds in the Middle East,” the chief correspondent of a major German television network tweeted after Kerry’s press conference. Some in the press pack were rather less polite in their private summations, wondering, for lack of a plausible alternative, if the secretary is delusional or dumb.

Why is Kerry subjecting himself to failure after failure, even observers sympathetic to his goals are asking themselves. Is he heroically allowing himself to become discredited, wonder some (as they cast around desperately to explain the otherwise inexplicable), in the cause of keeping the contacts ongoing, because to admit defeat would be to leave a vacuum that extremists would rush to fill?

Solving the Israeli-Palestinian conflict is a laudable goal, and Kerry might initially have been forgiven a belief that he was somehow uniquely qualified to break the deadlock. But visit after visit should surely have long since underlined a few simple truths: The two sides mistrust each other. Each is more concerned with avoiding blame for failed talks than prepared to take risks in the faint hope of success. Netanyahu and Abbas are also both looking over their shoulders at rivals and bitter opponents poised to capitalize on any missteps. And the unchanging bottom line: The most that Netanyahu might conceivably offer Abbas, were they ever to actually get to the table, is less than Abbas might conceivably accept — less than Ehud Olmert offered in his unrequited bid for an accord in 2008.

Those inescapable truths are hard to reconcile with Kerry’s insistent assertions at the airport that a breakthrough is “within reach,” and that all it needs is “a little more work.”

Kerry’s boss, president and Nobel peace laureate Barack Obama, also tried to tackle the conflict at the beginning of his first term, but backed away fairly rapidly, and subsequently focused his efforts on other areas.

Word from Netanyahu’s office after the talks collapsed in late 2010 was that the prime minister was willing to extend the 10-month settlement freeze that had briefly brought Abbas to the table then, but that the administration did not believe there was much point. Since then, Netanyahu has dug in against preconditions, while offering to discuss all issues at the table, and expressing a readiness for releases of pre-Oslo Palestinian prisoners — phased releases, so that Abbas cannot simply come back to the table, secure the freedom of the pre-Oslo veterans, and walk away again. Abbas, for his part, evidently remains unmoved in his demands for a settlement freeze and a commitment that the talks would focus on a Palestinian state based on the pre-1967 lines.

For Abbas, the option of battling Israel in UN forums is plainly more attractive than negotiating with a Netanyahu constrained by senior coalition partners from the far-right Jewish Home party, and key officials in his own Likud party, who are staunchly opposed to territorial compromise. For Netanyahu, the goal in these latest talks would appear to have been to convince Kerry that he’s really, honestly, truly interested in a two-state solution, if only Abbas would step up.

But Kerry just refuses to be discouraged.

“I have been around long enough, and I have heard all the arguments against working for Middle East peace. It is famously reputed to be diplomatic quicksand. I am familiar with the cynicism and the skepticism,” he said last month at a World Economic Forum gathering in Jordan. “But cynicism has never built anything, certainly not a state. It is true that the challenge of peace is formidable. But let me say unequivocally: The necessity for peace is much greater.”

These are admirable sentiments, indeed. And if Kerry can defy all the skeptics and the cynics, drag Netanyahu and Abbas into a room together, and actually succeed in cutting a deal where all his predecessors have failed through the decades, he’ll deserve all the accolades that will surely come his way. And the apologies of all the cynics and skeptics.

For now, though, he looks like the hapless top diplomat from the world’s only superpower, gradually reducing the prestige of his office by making himself overfamiliar to two recalcitrant leaders over whom he plainly wields no particular influence.

In June 1990, one of Kerry’s predecessors, James Baker, resonantly declared that “the telephone number (of the White House) is 1-202-456-1414. When you’re serious about peace, call us.” Kerry’s message could hardly be more different. No need to call, he assures Netanyahu and Abbas. I’ll be back soon anyway.