Does a TikTok video document the deployment of United States armed forces to Israel in support of Israel's military response to Hamas' October 7, 2023 attack? No, that's not true: there was no reported deployment and the video is concocted from images four years out of date or from U.S. troop movements related to the U.S. war in Afghanistan.
The claim appeared in a video (archived here) where it was published by @771111jin on October 15, 2023 without title. It opened:
US Forces🇺🇸 on its way to help Israel🇮🇱~
(Source: TikTok screenshot taken on Tue Oct 25 01:04:48 2023 UTC)
The video is built from two images, but none of them are related to ongoing Hamas-Israel conflict. The first image has been used as an Ebay product description image for costume patches since at least since 2019. The second image is a stock photo service picture published on various sites at least since 2021, related to Afghanistan.
Even though President Joe Biden said "The United States has Israel's back," the US did not announce direct intervention in the Hamas-Israel war. Instead, the US is closely cooperating with Israel and has relocated military assets in the region closer to Israel/Gaza.