What is the USA's benefit stationing troops and hardware in Poland?

Question

https://www.yahoo.com/news/kremlin-says-u-military-build-poland-national-security-111330103.html

Who is paying for those expenses?

What is the USA achieving through this deployment?

Answer 1

• The main benefit is to prevent Russia from influencing Poland into its sphere of influence, via military threats.

  Stratfor usually covers this in depth, but in short, this is a long term (centuries old, predating USA) game. Core Russia as a nation state suffers from a geopolitical problem: it has no natural defenses in the West, thanks to North European Plain. This allows for an easy invasion route from the West, utilized by all sorts of enemies over the centuries: Germany, France, for that matter Poland itself in its heyday. At the same time, it allows for easy invasion by Russia, if it were so inclined, of Western Europe.

  As such, Russia's only or at least main viable strategic defensive approach to the West direction is to build a series of buffer territories that it influences - Belorussia and Ukraine in the near distance, Poland further off.

  This makes Russia interested in controlling Poland - thus, Poland being 'recruited' into Warsaw Pact during Cold War, as well as Molotov-Ribbentrop pact as well as earlier annexation of parts of Polish territory, both during 20th Century and earlier Russian Empire.

  Therefore, the main goal of NATO (and therefore USA) in Eastern Europe is to prevent Russia from strengthening itself, by denying it said control/influence of Eastern European states. And Poland is ideal for this - it holds geographical blocking position to the rest of Northern European plain; and it has strong anti-Russian sentiment in its populus, for both short term historical, long term historical, and religious reasons.

• Therefore, stationing troops is a two-fold signal:

  • To Poland (and the rest of Eastern Europe): "We are committed to your defense from Russia's enroachment, via threats or even attack". This makes Poles less likely to succumb to Russia's influence by threats.

  • To Russia: "We are committed to Poland's defense from your enroachment, especially from threat of attack. You attack Poland, you attack American troops. You really really don't want to do that, even if you'd be willing to attack Polish troops, as the former would make America's national will shift towards supporting war with Russia and give casus belli at the same time".

  • To Russia short term: "You stepped on our toes, in Ukraine, Syria etc... Now we step on your toes, by doing something you don't like. Pthththth".