With major diplomatic challenges in the offing and with US President Barack Obama warning in his AIPAC speech that “impatience [with the lack of a peace process] is growing, and is already manifesting itself in capitals around the world,” Israel needs to muster its most united and pragmatic leadership.In September, the Palestinians will demand, and likely receive, UN General Assembly recognition of a Palestinian state along the 1949 armistice lines. Though Obama has expressed his opposition to the move, European leaders have remained noncommittal.Largely a declarative motion, a General Assembly vote in favor of a Palestinian state backed by leading European countries would nevertheless be a blow to Israel’s standing in the international community, pushing it closer to pariah state status, and perhaps creating empathy for a new phase of Palestinian violence. The boycott, divestment and sanctions (BDS) campaign against Israel would gain greater support, as could international “lawfare” against IDF officers and Israeli ministers traveling abroad, and against international and Israeli corporations that do business beyond the Green Line.Though important, public diplomacy – even as peerlessly demonstrated by Prime Minister Binyamin Netanyahu in his address to the joint session of Congress on Tuesday – can never hope to combat all of the caustic bias leveled against Israel in so many corners of the world. The formation of a unity government that includes the center-left Kadima, however, would send out a powerful message that the Israelis are united in their desire for peace and a two-state solution, would signify that the government speaks for the mainstream consensus and is not the prisoner of radical views, and would enable Israel to present consensual, reasonable demands of its own.Many in the world are under the impression that the current tension between the Obama administration and Israel is to be blamed on Netanyahu’s ideology, and that a more left-wing government would be more forthcoming. In reality, however, a large proportion of the Israeli electorate is troubled by the idea, in the current climate of regional instability and with Fatah now aligned with Hamas, of a new push for negotiations on the pre-stated basis of a withdrawal to amended pre-1967 lines and in the absence of a similarly firm demand that the Palestinians abandon the demand for a “right of return.”Negotiations must yield a complete resolution of the conflict and an end to all outstanding claims. The Palestinians must know that they cannot “pocket” territorial concessions while carrying on the struggle against Israel. Therein lies the problem with the US president’s recent policy address to the State Department – the recommendation that talks focus first on resolving borders and security, while leaving Jerusalem and refugees for later. It will be seized upon by the Palestinians as enabling them to continue to “dream” of the impossible demand for millions to “return” to Israel.Practically speaking, numerous obstacles stand in the way of a national-unity government, some of which have more to do with narrow party politics and egos than genuine policy considerations or the greater national good. Mutual respect between Netanyahu and opposition leader Tzipi Livni is in short supply. Kadima’s ability to set itself apart from the Likud ideologically might be hurt if it were to enter the coalition. And Livni has complained often of the incorrigibility of Netanyahu’s government and argued that early elections are the only remedy. While Netanyahu did call during his speech to the Knesset on Herzl Day for national unity, the reality is that the government is remarkably stable. Even the possible indictment of Foreign Minister Avigdor Lieberman, which would force him to relinquish the Foreign Ministry portfolio (he would remain an MK), does not threaten this stability. So the unity imperative is not compelling from the Likud’s point of view either.Both Netanyahu and Livni need to rise above such calculations for the sake of the nation. The world must be convinced not to endorse a Palestine unreconciled to Israel’s right to existence as the homeland of the Jewish people. National unity, coupled with a consensual diplomatic position, is the best vehicle to counter this threat.In his speech to the Knesset on May 16, before he left for Washington, Netanyahu hinted that Israel would be ready to dismantle settlements outside the large blocs in exchange for a genuine peace; he spoke along similar lines in Washington on Tuesday. With Kadima in the government Netanyahu would be able to flesh out his vision of future borders and set his red lines without fear of losing his coalition.In 2008, in negotiations with Palestinian Authority President Mahmoud Abbas, Livni stood firmly against the partitioning of Jerusalem and the “right of return” for Palestinian “refugees.” Ideological differences between Kadima and Likud are, in the end, narrow. The national interest demands unity.