Israel and Hamas moved ahead on a key first step of the tenuous Gaza ceasefire agreement on Monday by freeing hostages and prisoners, raising hopes that the U.S.-brokered deal might lead to a permanent end to the two-year war that ravaged the Palestinian territory.

But thornier issues such as whether Hamas will disarm and who will govern Gaza — and the question of Palestinian statehood — remain unresolved, highlighting the fragility of an agreement that for now only pauses the deadliest conflict in the history of Israel and the Palestinians.