As with Ukraine, it's a David and Goliath kind of conflict and in both conflicts, the temptation for Goliath to escalate by leveraging scale is predictable, tempting and frought.

Iran is not David in this case. They’ve shown that their drone warfare is just a little bit under what the US military can provide. Remember that they destroyed a quarter of a trillion dollars radar installation. And the US has spent billions on munitions. The US can’t actually keep going in this war.

I once compared the historic GDP values, and IIRC if Iraq-vs-US in 2003 is 1x baseline, then Iran-vs-US today is 7x. Plus Iran (today) has 2x the population and 3x times the land area than Iraq (today).