OK...but what about being granted citizenship magically makes someone more trustworthy to be in an operational unit in a position that doesn't require a clearance? The process of going from being a green card holder to a citizen isn't some incredible transformation where you are injected with 'Murica loving freedom blood.
Btw, infantry and armor MOSs don't require clearances...if somebody loves America enough to have THAT be their path to citizenship, I'm all for it.
Same goes for being a deck seaman now that I think about it.
Because following that path to its logical conclusion, any naturalized citizens of Iranian, Chinese, or Russian ancestry should be automatic down checks for any clearance.
While we're at it, throw in Taiwan, either Korea, maybe even Japan, certainly any former Soviet Union state, just about all of the Middle East, Pakistan, etc.