For the leaders of both Hamas and Israel, ending the war in Gaza has become a deadly game of survival.The terms on which the war finally ends could largely determine their political future and their grip on power. For Hamas leader Yahya Sinwar, even his physical survival.It’s partly why previous negotiations have failed. It’s also why the question of how to permanently end the fighting has been put off to the last stages of the plan outlined by US President Joe Biden on Friday.That transition between talks on a limited hostage-for-prisoner deal to discussions about a permanent…