Obama Casts Doubt on Chances of Gaza Cease-Fire

WASHINGTON — President Obama on Friday demanded that Hamas release a captured Israeli soldier unconditionally and expressed pessimism that another cease-fire could be reached because of the deep reserves of mistrust between the two sides.

Speaking at the White House, Mr. Obama said the seizure of the soldier just after the last cease-fire went into effect would make it difficult for Israelis to trust in any future truce. He added that Hamas had to discipline its own side if it hoped to advance its interests.

“It’s going to be very hard to put a cease-fire back together again if Israelis and the international community can’t feel confident that Hamas can follow through on a cease-fire agreement,” Mr. Obama told reporters in the briefing room. He dismissed questions about which faction of Hamas may have been responsible. “If they can’t have control of them and, just moments after a cease-fire is signed, you have Israeli soldiers being killed and captured,” he said, “it’s hard for Israelis to feel confident that a cease-fire can be honored.”

Mr. Obama weighed in shortly after the 72-hour cease-fire brokered in part by Secretary of State John Kerry fell apart, and he defended Mr. Kerry against what he called “nit-picking” and “unfair criticism.” He also expressed continuing concern for the civilian casualties among Palestinians, saying, “It’s heartbreaking to see what’s happening there.”

The president seemed to be struggling to find a balance in the fighting in Gaza. “It’s hard to reconcile Israel’s legitimate need to defend itself with our concern for those civilians,” he said. “And if we can pause the fighting, it’s possible we may be able to arrive at a formula that spares lives and also ensures Israel’s security. But it’s difficult, and I don’t think we should pretend otherwise.”

Mr. Obama, who appeared in the briefing room shortly after a phone call with President Vladimir V. Putin of Russia, also said there were limits to what the United States could do, beyond the economic sanctions already imposed, to stop the Kremlin’s intervention in neighboring Ukraine’s civil war. And he seemed to question Mr. Putin’s rationality.

“Short of going to war, there are going to be some constraints on what we can do if President Putin and Russia are ignoring what should be their long-term interests,” he said. “Sometimes people don’t always act rationally, and they don’t act on their medium- and long-term interests.”

Responding to questions from reporters, Mr. Obama defended his own much-criticized leadership in the world.

“If you look at the 20th century and the early part of this century, there are a lot of conflicts that America doesn’t resolve,” he said. “That’s always true. That doesn’t mean you stop trying.”

He added: “There’s a big world out there. And as indispensable as we are to try to lead it, there’s still going to be tragedies out there, and there will be conflicts.”