It (normally) has an effect on the military calculus - e.g. if the US weren't allowed to have military bases in these countries, the possibility to take such action seems less plausible.

You need to think that all the way through. The answer is obviously yes. Yemen is a perfect example. Iran is obviously as well. Afghanistan another great case. It is certainly possible to resist US pressure. Iran is asking the gulf countries to do that. Imagine how much better they would all be able to resist the US together as well, better than each alone.