Sure, but Western Europe has the same interests and can do the legwork itself.
Once an European security analyst one said that Russia and China are playing chess with the US and the EU, while the EU is playing backgammon.
He doesn't think in terms of Biden or Trump, but in terms of opportunity. You should really think of Russia as a modern feudal state where Putin shares the country's resources with the oligarchs. The only difference is that it isn't farmland, but oil and gas. He doesn't need to appease them. He can run a show trial, have them shot on a bridge, poison them, just like he did with Khodorkovsky, Litvinenko, Nemtsov, Skripal, Navalny and others.
Vladimir Sorokin once said that the basis of modern Russia was set by Ivan the Terrible.
https://www.publicbooks.org/dress-up-games-with-russian-hist...
One should read post/modern Russian literature in order to understand modern Russia. It's also very good. I love Russian literature.
In practice, it's unclear if the presence actually does much. But at the very least it ensures that an attack against NATOs eastern Block would be an attack against troops from many countries -- thus, many NATO countries can claim to have been attacked.
5k troops isn't much, but it proves a commitment. All NATO really has to prove is that we stand together -- then Russia won't attack NATO members.
No, it can't, conventionally in the short term; in part, that's low spending, and in part it is specialization within NATO, but neither of those are easily unwound in the short term.
Against Russia specifically, as opposed to a generic hypothetical major conventional regional threat, there is also the problem that UK + France probably have an insufficient nuclear deterrent force, which is a problem the US, even if we’d like them to increase domestic military spending, doesn't want addressed.