Well, plenty of allied soldiers in both Iraq and Afghanistan wars have been sentenced for war crimes, during the war on terrorism.

Take the Mahmudiyah case: https://en.wikipedia.org/wiki/Mahmudiyah_rape_and_killings

Lifetime imprisonments

The difference here is that when Israel does so - which is exceedingly rare - it is merely a slap on the wrist. Weeks to months in prison. Where's the deterrence in that?