get back whats theirs
Don't be silly. A hostile state with no claim be it historical, legal or moral, invaded it, and (unlike the Rhineland post-Versailles). And of course in the recent referendum (a referendum, not a 30s 'plebiscite'), 99.8% of the residents (including those with Argentinian nationality) confirmed that they want the status quo to remain.
tad hypocrit
No.
You're going off-topic however. Germany started WWII, not Poland, not Britain, and the warning signs were there not just at the illegal invasion of Sudety but also earlier at the illegal invasion of the Rhineland.