All it took was 90 seconds for weeks of tortured diplomacy to unwind in spectacular fashion. President Donald Trump's Oval Office thrashing of Ukraine's Volodymyr Zelenskyy on Friday laid bare the limits of a full-court press by America's allies aimed at reshaping Trump's determination to end Russia's invasion even if the terms are not to Ukraine's liking. It also stressed the profound ways Trump feels emboldened to redirect US foreign policy priorities toward his America First agenda in ways that extend well beyond those of his tumultuous first term. The sudden blowup was the most heated public exchange of words between world leaders in the Oval Office in memory, as the usual staid work of diplomacy descended into finger-pointing, shouting and eye-rolling. The encounter left the future of the US-Ukraine relationship, and Kyiv's ability to defend itself in the brutal conflict with Russia, in mortal jeopardy. You either make a deal or we are out, Trump told Zelenskyy, underscoring