By Humeyra Pamuk, Arshad Mohammed and Jonathan Landay WASHINGTON (Reuters) – The United States has not given Israel a firm deadline to end major combat operations against Hamas in Gaza, and if the war ended now, the Islamist group would continue to pose a threat, White House national security aide John Finer said on Thursday. “We have not given a firm deadline to Israel, not really our role. This is their conflict. That said, we do have influence, even if we don’t have ultimate control over what happens on the ground in Gaza,” Finer told the Aspen Security Forum in Washington. Israel has two o…