People of Alaska will declare independence (with little help of Russian tourists, journalists, and some honest news). This will not trigger a war, right? Independent Democratic People Republic of Alaska will join Russian Federation next day after that. Job is done.
Just in case the original Alaska message was not sarcasm.
States can not secede from the US. Do a little reading on this. And if they try there will be action from the rest of US starting from police and up to full blown military enforcement. And if Russia will try to protect said state we will have nice little nuclear war. Say bye to your iPhone and Hacker News.
Crimea cannot secede from the Ukraine. Was not a problem, solved with lots of honest news made by Russian journalists with help of Russian green (khaki) tourists.
Ukraine started full-blown military operation. Not a problem, because war was triggered on Donbass, part of Ukraine which is not annexed.
Ukraine is post-nuclear country, so it can nuke Russia. Not a problem, because of fear of MAD.