Ehud Barak, Israel’s defense minister and the leader of the Labor Party, announced Sunday that he would remain in the government, stabilizing Prime Minister Ehud Olmert’s coalition despite last week’s harsh report on the political and military leaders’ handling of the Lebanon war in 2006.

Also Sunday, Egyptian troops closed the border with the Gaza Strip, ending 11 days of free movement and frenzied buying by Palestinian residents of the blockaded territory — at least for the time being. Egyptian forces were allowing Gazans and Egyptians to cross the border to return home, but prevented any new cross-border movement.

Egypt had made earlier unsuccessful attempts to close the border, but was thwarted by gunmen affiliated with Hamas, the militant Islamic group that took control of Gaza last summer. But after a visit to Cairo by senior Hamas officials, the Hamas gunmen apparently were cooperating with the Egyptians on Sunday.

With regard to Mr. Olmert, Mr. Barak said during party primaries last May that he would seek to form a new government or to set a date for early elections if the prime minister did not resign by the time the government-appointed commission, looking into the conduct of the war against the Lebanese Hezbollah militia, issued its final report. A scathing preliminary report on April 30 assigned personal responsibility to the prime minister, the former defense minister and the former army chief of staff for flawed conduct during the war.

Of the three, only Mr. Olmert did not resign. Mr. Barak replaced the wartime defense minister, Amir Peretz, in June.

Explaining his decision to stay on, Mr. Barak cited the challenges facing Israel, among them the continued threat from Hezbollah, which, Israeli officials contend, has fully re-armed since the war.

Mr. Barak also mentioned threats from the Gaza Strip, Syria and Iran, as well as the need to improve operations of the army and the negotiations, which the center-left Labor Party supports, with the West Bank-based Palestinian Authority led by President Mahmoud Abbas.

“I promised I would do what I think is good and right for the country,” Mr. Barak told reporters before the weekly cabinet meeting, “And I think at this moment this it what is good for the country.”

Analysts here had assumed that Mr. Barak, a former prime minister who is likely to run for the post again, would not want to leave government for the political wilderness right now. Polls over the weekend also suggested that a majority of Labor supporters did not want Mr. Barak to quit.

Mr. Olmert’s term is supposed to end in November 2010, though few expect it to last that long. There are differences within the government over the peace talks with the Palestinians, and the prime minister — under criminal investigation for various possible violations — is generally unpopular.

Mr. Barak said Sunday that he would deal with the harsh conclusions of the war report, named for the retired Judge Eliyahu Winograd, who headed the commission, “at the proper time and set a time for elections.” But he did not suggest a date.

Members of the opposition excoriated Mr. Barak for propping up Mr. Olmert, who leads the centrist Kadima Party. There were some critics in Labor, too. “This was an opportunity for the Labor Party and its leader to rectify the situation in the eyes of the public, which expects leadership, morality and ethics,” Eitan Cabel, a member of Parliament and the party secretary, told Army Radio.

Still, as a former army chief of staff and Israel’s most decorated soldier, Mr. Barak is considered by many here to be well equipped to fix problems in the country’s military. Though famed for past victories, the army was castigated by the Winograd Commission for its poor performance in the 2006 conflict.

Yet Mr. Peretz, the former defense minister and trade union leader, said Thursday that figures who had served in major posts in the past, like Mr. Barak, were largely to blame “for policies and failures that had built up over years.”

The political echelon also came in for criticism in the final Winograd report, though the most hotly debated wartime decision, regarding the start of a ground campaign in the last days of the war, was deemed “reasonable” by the commission, taking some of the heat off Mr. Olmert.

Mr. Olmert said Sunday that the report was “not a source of joy; there was none anywhere, certainly not with me.” But there were “achievements alongside the failures,” he said, adding: “We must neither exaggerate the achievements nor understate the failures. Rather, we must treat them with all due seriousness and gravity.”

Israel’s border with Lebanon has been mostly quiet since the monthlong war, but on Sunday evening Israeli soldiers exchanged fire with a number of people near the border who turned out to be Lebanese drug smugglers, an army spokesman said. Reports from Beirut said that one Lebanese man had been killed and another seriously wounded.

In Gaza, Ahmed Youssef, an adviser to the Hamas administration, said that the breach of the border with Egypt on Jan. 23 was “a wake-up call to those avoiding listening to the people’s cry.”

Hamas militants blew up sections of a wall along the Egyptian border days after Israel sealed its own border crossings with Gaza in response to intensified rocket fire from the strip. Hundreds of thousands of Palestinians are thought to have crossed into Egypt to stock up on supplies.

In a veiled threat directed at Israel, Mr. Youssef said: “This time we moved toward Egypt. Next time we don’t know where to — maybe Erez, maybe Karni,” naming two of the closed crossings between Gaza and Israel.