CNN — US officials were mum in the immediate moments after the Israel Defense Forces (IDF) announced it was investigating whether a strike in Gaza had taken out Hamas leader Yahya Sinwar.

If Sinwar is in fact confirmed dead, the ramifications for the Biden administration would be momentous. His potential death, perhaps more than anything else, the singular event that many US officials had pointed to as the biggest potential game-changer in the Israel-Hamas war that has now been ongoing for more than a year.

With a ceasefire and hostages deal to pause the war stubbornly stuck for months, senior administration officials had hung onto hope that Sinwar might one day be taken out – and that that could open up doors that simply would not be otherwise. US officials have looked at Sinwar, simply put, the scalp that Israel needs most to be able to declare that they are done with the Gaza war.

Even in discussions of a so-called “all for all” deal – the idea that every hostage held by Hamas would be released in exchange for every Palestinian prisoner that Hamas wants freed – which is widely viewed as far-fetched – some US officials had mused perhaps such an idea could be remotely viable if Sinwar were dead.