The new secretary of state’s exertions — reminiscent of predecessors like Henry A. Kissinger and James A. Baker III — have been met with the usual mix of hope and skepticism. But with so much of the Middle East still convulsing from the effects of the Arab Spring, Mr. Kerry’s efforts raise questions about the Obama administration’s priorities at a time of renewed regional unrest.

The Israeli-Palestinian conflict, once a stark symbol and source of grievance in the Arab world, is now almost a sideshow in a Middle East consumed by sectarian strife, economic misery and, in Egypt, a democratically elected leader fighting for legitimacy with many of his people.

“The moment for this kind of diplomacy has passed,” said Robert Blecher, deputy director of the Middle East and North Africa Program of the International Crisis Group. “He’s working with actors who have acted in this movie before, and the script is built around the same elements. But the theater is new; the region is a completely different place today.”

Administration officials no longer argue, as they did early in President Obama’s first term, that ending the Israeli occupation and creating a Palestinian state is the key to improving the standing of the United States in the Middle East. The Israeli-Palestinian conflict is now just one headache among a multitude.

And yet Mr. Kerry, backed by Mr. Obama, still believes that tackling the problem is worth the effort: five visits to the region in the last three months. The most recent trip involved nearly 20 hours of talks, stretching almost until dawn, with Prime Minister Benjamin Netanyahu of Israel and Mahmoud Abbas, the president of the Palestinian Authority.

Former administration officials defend that conviction. Mr. Kerry’s focus, they say, makes sense precisely because of the chaos elsewhere. With little leverage over Egypt and deep reluctance about intervening in Syria, the Israeli-Palestinian conflict is one place that the United States can still exert influence, and perhaps even produce a breakthrough.

“You don’t have instability between the Israelis and Palestinians right now,” said Dennis B. Ross, a former senior adviser to Mr. Obama on the Middle East. “But if you don’t act, there’s a risk that the Palestinian Authority will collapse, leaving a vacuum. And if we know one thing about vacuums in the Middle East, they are never filled with good things.”

Resuscitating the peace process, he said, is also vital to Jordan, which is reeling from the wave of refugees from Syria and can ill afford a new wave of Palestinian unrest in the neighboring West Bank.

What is less clear is whether the Arab upheaval has made a peace accord between the Israelis and Palestinian any less elusive. Some analysts say the instability has made Mr. Netanyahu and Mr. Abbas eager to resolve their dispute, while others assert that both can use it as a pretext to avoid making the hard choices needed for a deal.

“I think both sides look at what’s happening in the region right now and think, ‘Maybe we’re better off putting ourselves in a more stable situation with each other,’ ” said a senior Western diplomat who spoke on the condition of anonymity because of his involvement in what Mr. Kerry has demanded be confidential discussions.

But several Israeli analysts said the reverse was true: the unrest has made Israel more concerned about security than about taking risks to advance the peace process. Sallai Meridor, a former Israeli ambassador to the United States, said most Israelis would rank Syria, Iran, Egypt and Jordan above the Palestinians in terms of “importance and urgency.”

A day after Mr. Kerry concluded 13 hours of talks with Mr. Netanyahu, Israeli newspapers were dominated by images of the vast protests in Egypt. Five of the six five major daily papers did not even carry front-page reports on Mr. Kerry’s diplomacy.