What I eventually decided was that there actually was no reason. Or to put it more specifically, the idea of invading Iraq and overthrowing its government had become a sort of idée fixe in 2002 in Washington, DC. Once it became clear that people at the highest levels of the administration really, really wanted to do this there was a kind of unannounced contest to come up with a reason why it was a great idea. It’s started to feel like that again today. Donald Trump is a bit obsessed with possessing Greenland. And that’s creating a kind of gravitational pull to come up with reasons to justify the idea.
You left out the “friendly country, in an act of imbecilic vandalism.”
Edit: Also, attacking Denmark is attacking a NATO member. It’d be interesting if Trump found himself in a Ukraine invasion situation, except facing an enemy that’s larger and richer.