In a country where most prime ministers lose power after about three years, Benjamin Netanyahu's political survival skills have impressed many. Heading a fractious coalition, he has stood up to American pressure to halt West Bank settlements, diverted blame for collapsed peace talks and deftly navigated challenges from his right flank.

But though his coalition is viewed as stable for now, the Israeli leader, nearing the two-year mark, is starting to show signs of vulnerability.

Polls this month put Netanyahu's approval rating at a new low of 32% and found that if elections were held now, his conservative Likud Party would trail the centrist Kadima by seven parliamentary seats. Experts link the dip to rising gasoline prices and growing fear about Israel's isolation in the region.

Amid international impatience over stalled peace talks — including a reported dressing-down last month by German Chancellor Angela Merkel — Netanyahu is floating what aides promise will be a "bold" new initiative to end the conflict with Palestinians.

But newspaper pundits and political analysts have recently taken to describing Netanyahu as "grumpy," "irritable," and "depressed." They mocked his recent call for ministers to try harder to publicly tout his government's achievements as a sign of desperation.

Kadima Party leader Tzipi Livni compared the prime minister in one interview to an "animal caught in the headlights."

Netanyahu's supporters dismiss the criticism as politically motivated, spread by rivals who have an eye on his job. But they acknowledge that the prime minister is at a crucial juncture.

"Is he running scared? I don't think so," said Likud foreign policy chief Zalman Shoval. "But there is pressure. And it certainly makes it necessary for a lot of heart-searching and perhaps reappraisals."

One challenge for Netanyahu, Shoval says, is that the prime minister heads a coalition that is more conservative than he is. "Netanyahu is a centrist, despite the image," Shoval said. "He's not a real right-winger in the sense that others in his own party are."

Yet in trying to strike a balance, Netanyahu seems to have satisfied neither side of the political spectrum. Last month, the liberal Labor Party quit his coalition, saying Netanyahu is not serious about negotiating a peace deal.

At the same time, conservative settler groups have launched a media campaign against Netanyahu, criticizing him for not allowing West Bank settlements to expand faster.

Netanyahu's own foreign minister, Avidgor Lieberman, has been clashing frequently and publicly with him. Some say Lieberman, head of the right-wing Yisrael Beitenu party, may be preparing to bring down the coalition government so he can challenge Netanyahu in new elections.

In a rare public display of frustration, Netanyahu lashed out at his conservative critics this month during a Likud Party meeting, saying they "don't understand the reality they are living in" and warning that international pressure and isolation would only get worse if Israel expands the settlements.

The proposed peace initiative is expected to be announced by May and may serve as the strongest sign yet that Netanyahu is feeling the pressure. Aides have billed the announcement as a major event, likening it to Netanyahu's 2009 speech at Bar Ilan University when he endorsed a two-state solution for the first time.

Details of the plan are not yet clear. Some have suggested that Netanyahu will back an interim peace plan giving Palestinians a provisional state and temporary borders. But Palestinians have rejected similar ideas.

American officials say they have not been briefed on the details.

"There's a suggestion that there may be new Israeli ideas," said a senior Obama administration official. "We haven't seen them yet. It's unclear what the prime minister will want to put forward. But progress can only come through direct negotiation and can't come unilaterally."

Members of Netanyahu's inner circle are urging him to move quickly.

"We have to be proactive before calamity hits, before we are isolated," Intelligence Minister Dan Meridor told Army Radio on Monday, noting that Israel narrowly avoided a U.N. condemnation of settlement activity last month, thanks only to a U.S. veto in the Security Council.

The initiative has reignited a debate about whether the prime minister is on the verge of shifting to the left and making a historic compromise toward a two-state solution, or merely buying time to appease the international community.

Similar questions arose after the Bar-Ilan speech and again during September's short-lived direct peace talks, when Netanyahu raised eyebrows by calling Palestinian Authority President Mahmoud Abbas his "partner in peace."

Both times, critics say Netanyahu later hardened his positions to shore up conservative political support, and some see similar moves happening again.

This week, even as his aides talked about a peace plan, the prime minister took a provocative walk in the Jordan Valley, in the West Bank, angering Palestinians by vowing to maintain a military presence there even after Palestinian statehood.

He is also reportedly negotiating to invite into his coalition members of the National Union Party, viewed by many as among Israel's most extreme far-right movements.

Analysts say such a strategy will be harder today because unrest in Arab nations across the region has left many Israelis feeling insecure and questioning what has been achieved in the last two years toward ending the conflict.

"The public is beginning to feel that the government is treading water," said Yehuda Ben-Meir, a former deputy foreign minister and fellow at Tel Aviv's Institute for National Security Studies. "If he doesn't make a serious diplomatic move sooner or later, he will be in trouble.… The public doesn't like wishy-washy."

Others say Netanyahu should articulate his vision for a peace plan and spend less time avoiding the kind of internal political instability that marred his first tenure as prime minister in the 1990s, which was cut short after three years by the defection of right-wing supporters.

"He has survived two years and his coalition isn't showing any signs of falling apart," said Haifa University political science professor Israel Waismel-Manor.

"The problem is that he created a coalition that prevents him from taking care of the other things that interest him.... He is very concerned about the situation. The question is whether he is concerned enough or courageous enough to do something about it."