JERUSALEM — Israeli Prime Minister Benjamin Netanyahu and the centrist opposition party Kadima formed a surprise unity government Tuesday, extinguishing plans for early elections and cementing Netanyahu’s position as the strongest Israeli leader in years.

The deal gives the governing coalition a vast parliamentary majority, fortifying Netanyahu’s mandate as he presses for possible military action against Iran’s nuclear sites, an idea that has faced growing domestic criticism. It could also shift the hawkish coalition toward the center, granting Netanyahu room to weather threats of revolt by right-wing factions and perhaps leeway to offer concessions to the Palestinians.

The announcement of the secretly negotiated deal appeared to stun even senior Israeli officials, who hours earlier had been moving to dissolve parliament and prepare for early elections in September. Netanyahu, whose Likud party had been expected to win easily, said Tuesday that the agreement with Kadima leader Shaul Mofaz allowed him to swiftly deliver what he had pledged to create after the elections — a broad-based alliance that would ensure stability.

“I realized that it was possible to restore stability without holding elections,” Netanyahu said at a joint news conference with Mofaz. He called the deal “good for security, good for the economy and good for the people of Israel.”

The agreement triggered a new round of speculation about the chances of an Israeli strike on Iran’s nuclear program, which Israel deems an existential threat. Some commentators said the deal meant that Netanyahu had cleared his calendar to prepare for war. Others said the sudden ascent of Mofaz, a former military chief and defense minister who has expressed opposition to a unilateral Israeli attack, made war less likely.

Neither man shed much light on the subject Tuesday, saying only that they would discuss it seriously. In any case, some observers said, the new coalition’s majority — 94 out of 120 seats in parliament — would give new muscle to Netanyahu’s push for tough action against Iran, allowing him to say more firmly than ever that he represents the Israeli point of view.

“The decision that has been taken last night sends a very clear message that this is the prime minister and this is the government which people will have to deal with for a long time,” said Zalman Shoval, a former ambassador to the United States and longtime adviser to Netanyahu. “And this is a message both to our friends and to our foes.”

Political considerations

The immediate aim of the deal, under which Mofaz became a vice prime minister, is to push through a replacement for a law that exempted ultra-Orthodox seminary students from military duty, an issue that had divided Netanyahu’s coalition. The alliance was also split over court- ordered evacuations of West Bank settlements, and right-wing Likud members had sought to oust Netanyahu’s key partner on the Iran issue, Defense Minister Ehud Barak, who oversees such evacuations.

“It makes the makeup of the government more centrist and representative of the whole gamut of Israeli society,” Dan Meridor, a deputy prime minister, said in an interview. “We have more flexibility in making decisions and not being dependent on small parties with special agendas.”

For Kadima, whose representation in the Israeli Knesset after elections was expected to shrink from 28 seats to 12, the unity deal amounted to political resuscitation, at least until elections in October 2013. Kadima is a Likud offshoot that was established in 2005, and the deal raised the possibility that it might eventually be reabsorbed.

“I will be involved with all the national and security issues of the state,” Mofaz told reporters, who asked why Kadima did not secure more than one cabinet seat under the deal. “This is influencing.”

Both Kadima and Likud were viewed as interested in blunting the rise of the Labor Party, which had promised to focus on the socioeconomic issues that preoccupy many ordinary Israelis, and of a new party formed by former television presenter Yair Lapid.

Despite the obvious motivations for both sides, the unity deal came as a shock, particularly in light of Mofaz’s repeated insistence that he would never join a coalition led by Netanyahu, whom he recently called a “liar.”

Shelly Yacimovich, the Labor Party leader, called it “the most ridiculous zigzag in the history of Israeli politics.” Danny Danon, a right-wing Likud member, decried the agreement as “moving the coalition to the center and reviving the political corpse that is the Kadima party.”

Voice on security issues

Mofaz will now sit in Netanyahu’s inner security cabinet, giving him a voice in key policy decisions. On Iran, what that voice will be is unclear: Mofaz, who was born in Iran, has backed recent criticism by former Israeli security chiefs who have accused Netanyahu and Barak of wanting to rush into war. But as a cabinet minister in 2008, Mofaz said a strike on Iran would be “unavoidable” if the country pursued nuclear weapons.

Shoval said there were only “minor differences” between Mofaz and Netanyahu on how to deal with the Iranian nuclear program. Both agree that it is a serious threat and that all options — military and diplomatic — should be considered, he said.

“I think that was probably the most important element in Mr. Netanyahu’s decision — to come not only with a united but strongly supported political front in tackling the Iranian issue, should Israel be forced to take military steps,” Shoval said. “Or even if not, in order to silence any impression which may have been created in recent weeks that Israel is not united in its stance.”

The unity deal also included a pledge to “renew the political process with the Palestinian Authority.” It was clear, though, that Netanyahu and Mofaz had not settled what that meant. Mofaz said Tuesday that he had drawn up an interim peace agreement based on borders and security. But he said he would need to discuss it further with Netanyahu, who reiterated his long-held stance that Israel is open to discussions without preconditions, such as a freeze on settlements.

“The question is: Is there an ideological change in Netanyahu’s positions?” said Gabriel Sheffer, a political scientist at Hebrew University. (© 2010 The Washington Post Company 05/08/12)