You mean like Russia has no ability to project power in Cuba, Venezuela, Nicaragua (and now) El Salvador?
We have many assets in the form of NATO members near and on the Black Sea, all of whom are seriously shaken by what Putin is doing. There are also ample opportunities to pressure Putin elsewhere, first of all with really hard economic sanctions and helping Ukraine, then attacking his client states (Syria) and going after other positions in Europe (Belorussia, Kaliningrad, Abkhazia and Ossetia). Afghanistan is a sideshow at the moment, and as far as I can tell we will have few (if any) troops there by the end of the year.
We don't lack the means: we lack the will.
How can we get a carrier group into the Black Sea and hold it?
Not the same as Cuba or the South American countries. Though the fact we let them slide away is very dangerous.