US President Joe Biden makes it clear: This is just the beginning. It is unlikely that the attacks by pro-Iranian groups could stop completely after the US military action.
Things could become particularly dangerous if another attack by militias - perhaps due to poor planning and execution - killed more US soldiers. The next step would then be a direct attack on Iran's Revolutionary Guard - and thus a dramatic expansion of the conflict. The deeper the USA is drawn into the new confrontations with Iran, the greater the danger that they will develop a dynamic of their own.