People gripe about twitter, and deservedly so (evergreen opening line), but it is mighty handy. Latest examples:
I have been worried since November and was reassured when I saw Obama sending the troops early.
Once I saw that the US was sending a Brigade Combat Team, I began to wonder about where it might go. A BCT with 3500 troops is larger than the 1k troops that are the US commitment to Poland, as agreed to at the Warsaw Summit. So, I began to wonder if some of the troops might be going elsewhere to fill out the allies who are moving slower (that would be you, Canada, and nearly everyone else). That is, there are two needs: now and later. Now, to deny Putin any faits accompli. Later, as the allies may not be sending enough to reach the 1k in each spot AND for extended deterrence (the tripwire) to really work, Russia should be concerned about bumping into American troops, not just any NATO soldiers.
So, I am pleased, although I fully recognize that Trump can reverse this. But to do so, he would first run into SecDef to be Mattis who would certainly support NATO here. As I discussed before, it would be far easier for Trump to say " the troops are coming sometime, just like my tax returns." Much harder to pull out troops sent to a NATO mission. Not impossible, but it would be visible and politically charged in Europe and Washington, DC. The stakes are high enough that Mattis would be forced to wonder if it made sense to stick around.
So, not perfect, but not bad either. This US force will be sending troops hither and yon in Eastern Europe to provide stability. Should Russia be threatened by this? Frustrated? Yes, as it weakens their leverage and perhaps denies Putin some opportunities. But threatened? One BCT is not capable of invading Russia, and, by the way, Russia has those nuke thingies that are sufficient for deterring any and all peer-states from invading (can't say the same for terrorists/secessionists/domestic challenges). So, Russia can say it is threatened, but the force here is modest enough that it should not activate any spirals. Also, Russia moved first, so NATO/US not moving would be provocative in a different way: "here's an open door, I dare you to walk inside."
Anyhow, I am glad that social media allows me to engage with many different kinds of actors, including the units doing the stuff that I have been talking about.
Update: Stars and Stripes has a good piece on this, noting that the deployment is moving so fast that they didn't have time to change the camoflauge on the tanks from desert (Afghanistan, Iraq) to forest green (East Europe). Gives you a hint that Obama pushed this quickly after the election.