The question of Putin's "off-ramp" -- or decisions that allow him to end the fighting without admitting defeat -- has exercised Western policymakers and foreign policy experts since the very start of the war in February.I think the Russians are in a serious world of hurt," added Cohen, an expert at the Center for Strategic and International Studies at the US-based Johns Hopkins University.But Biden said Thursday that he believed Putin was "not joking" with his threats, adding that it was difficult to imagine how this did "not end up with Armageddon."- 'Journey to hell' -With the Russian president continuing to raise the stakes, another "off-ramp" is one that sees Putin bundled out of power, either through a popular uprising or -- more likely -- a "palace coup" in which he is replaced by a rival."The key question is whether Russia's elites and broader society are prepared to accompany their president on this journey to hell," wrote Tatiana Stanovaya, a Russian political scientist at the Carnegie Endowment for International Peace, a US think-tank."