Iran can establish deterrence with asymetric means and let's not forget, that contrary to what most americans think, Iran is not a backward hell hole like Somalia or Afeganistan. For a third world country we could say they have a competent R&D infrastructure, with a good number of STEM graduates every year (with roughly half of them being woman, which shows they are casting a wide net for talents).

They also have a lot of leverage points in their geography, in the fact that the US is at a historical low point in its military capabilities.

US and Israel strategy seems to be to completely destruct Iran's economy, but the problem is that this is a game where they can also shoot back.