Well It's not really clear, other than the Navy has been engaged in shooting down drones and missiles that are aimed at Israel, which is a direct intervention in the war. Having said that, when somebody shoots a missile there isn't that much time to figure out where it's going, and Iran, through its proxies, has been attacking our troops in Iraq and Syria for quite some time.
We seem to be getting ready to deploy ground troops, somewhere, in support of Israel's efforts.
And it's pretty clear that we're staging in case this goes regional in a fashion that we feel we need to get into.
It's interesting how we're rushing headlong into this, without much thought. Over the weekend, on one of the weekend shows, some politician was arguing that the US should raid into Gaza if we know where some American hostages may be held. I don't doubt, moreover, that we would.
Israel, for its part, has never overtly asked for US boots on the ground, or aircraft in the air, in any of its wars. And it hasn't needed them.
Caution. Deep water ahead.