A senior Biden administration official said Wednesday that the key to reviving talks on a deal to end the Gaza war was the Israeli military campaign in Lebanon last September.

“The catalyst for this intensive diplomacy was the defeat of Hezbollah, the ceasefire in Lebanon and the massive isolation of Hamas that got them back to the table and, for the first time, to accept a hostage list that, yes, this is who is going to be released in the deal that led to this ultimate breakthrough,” the official said.

According to the official, individuals from the incoming Trump administration, including his special envoy for the Middle East, Steve Witkoff, played a key role in the talks. Qatar and Egypt also played a crucial role, the official added.

The official was explaining the backdrop of what ultimately led to the Gaza deal finally being reached, highlighting Israel’s military campaign against Hezbollah in Lebanon last September.

Israel wiped out Hezbollah’s entire leadership, including leader Hassan Nasrallah, and humiliated the group in a two-day cyberattack on its communications network. This campaign was “extraordinarily successful,” according to the official, who added that the killing of Hamas leader Yahya Sinwar the following month was also significant. During October, Israel also responded to Iran’s second-ever direct attack on Israel by carrying out airstrikes that destroyed most of Iran’s missile production and strategic air defense systems, the official said.

And finally, the US-brokered ceasefire between Lebanese Hezbollah and Israel in November further isolated Hamas and Iran.

“It is just impossible… to overstate how significantly this region has changed,” the official said. “I think Israel has demonstrated it is probably… one of the most militarily powerful, capable, effective countries in the Middle East. This has significantly changed the equation.”