When it comes to post-election coalition building in Israel, the impossible alliances of yesterday routinely become the probable partnerships of today. Last week, for instance, it was clear that Labor was headed for the opposition benches. Its leader, Defense Minister Ehud Barak, publicly confirmed this. The party spoke with one voice: Labor needed to rehabilitate itself out of government. Now, Barak has been reconsidering. Wooed by Prime Minister-designate Binyamin Netanyahu in talks on Sunday, Barak did not say no, and the pair agreed to meet again - notwithstanding the Labor leader's indications to his colleagues on Monday that opposition was still the most likely eventuality. Similarly, the theoretical impossibility of ministers from Shas and Israel Beiteinu sitting together at the cabinet table - the former holding to rigid halachic formulations on marriage and conversion, the latter seeking to smooth the paths into Judaism for many of its immigrant constituents from the Former Soviet Union - now seems far from impossible. Scholarly and lawyerly finesses may well prove capable of bridging seemingly irreconcilable differences. Even the resolute insistence of Kadima's leader, Foreign Minister Tzipi Livni, that her party will not serve as a centrist fig leaf for a hawkish prime minister Netanyahu, may be wobbling just a little; certainly, there are more voices in her party this week than last quietly suggesting that "national responsibility" requires a rethink. IT'S NOT hard to discern the various players' motives. Netanyahu emphatically does not want to be stuck with a hawkish coalition - vulnerable to the conflicting demands of each component party, depicted at home and abroad as extreme, facing a substantial Knesset opposition relentlessly undermining him and seeking his ouster. Barak revels in his Defense Ministry job, regarding himself as a mature, experienced, wise head restraining and guiding more impetuous colleagues. Shas, for its part, is a party whose raison d'etre requires that it sit in government, ideally controlling ministries - such as housing, social welfare and education - where it can best channel funds for the particular needs of its voters. Likewise Israel Beiteinu, which, apart from Avigdor Lieberman's personal ambition for senior cabinet rank, knows it will be largely judged at the ballot box next time by the degree to which it served those basic life-cycle needs of its immigrant voters. For Livni, resisting Netanyahu's seductive promise of near-equal status is an act of high principle. Her assumption is that a narrow coalition will be discredited and will fail, paving the way for new elections and an outright Kadima success to erase the memories of last month's Pyrrhic victory. The most strenuous Kadima opposition to this strategy - led by Shaul Mofaz - comes unsurprisingly from those least contented with her leadership. ALL THIS tactical thinking amounts to politics as usual - maneuvering to best serve personal and party ambition. The question Netanyahu's various potential partners should ask themselves, however, is whether Israel can afford politics as usual right now. If Iran cannot yet build a nuclear bomb, it is certainly closing in on that goal. Operation Cast Lead plainly did not put an end to rocket fire from Gaza. Unemployment is soaring. And that is only the first trio of critical challenges. For Livni in particular, the choice is weighty. When it is formulating positions on settlements, on a strategy for dealing with Hamas and on facing the Iranian nuclear danger in the crucial next year or two, she might ask herself: Will Israel be better served by a narrow coalition, or by a government that demonstrably represents a wide electoral consensus? For all the shifts and reverses, signs are that Livni has irrevocably made up her mind, and that Kadima performed well enough under her leadership in the elections to respect her decision to go into the opposition and hold together for now. However, this choice may return to haunt her. It may prove unfortunate for Israel, for her party, and for her personally. Even when gauging her narrow interests, after all, there is no guarantee that a right-wing coalition will quickly crumble. And there is certainly no guarantee that, if it does, a new election will bring a better result for her party and its would-be prime minister.