Despite hopeful signals from U.S. President Donald Trump’s administration about a potential nuclear deal with Iran, the fundamentals don’t look good.

Trump recently said, and rightly so, that the U.S. would not allow Tehran any form of uranium enrichment capability (although top aides have sent mixed signals). Iran, conversely, makes the unconvincing claim that it would use enrichment capacity not to build an atomic weapon, but to feed nuclear power plants.

Israel, meanwhile, is sending blatant signals that it is ready and enthusiastic to launch strikes at Tehran’s nuclear facilities now, while Iranian air defenses are still weakened after two years of sporadic conflict. Trump is telling the Israelis to cool their jets (literally) while he tries to forge a peaceful arrangement. But he is equally clear that if talks collapse, the next step may well be joint U.S.-Israeli strikes.