President Obama is going to stop by Poland on his next European trip to reassure the Poles. Canada just send six CF-18s to Romania to help reassure Eastern Europe. The Danes have done likewise. Any student of extended deterrence and/or of NATO would caution Obama that reassure is a more or less thing and not something that will calm all frayed nerves.
During the Cold War, the US went to tremendous efforts to reassure Europe that the US would show up when the Soviets attacked. The most visible and costly manifestation of that was the deliberate placement of hundreds of thousands of Americans in harm's way as a tripwire. Remember, it was not just American soldiers, sailors, pilots and marines (not sure if Marines were based at all in Europe), but their wives (in the days of only or nearly only men in uniform) and their kids who went to German, Italian, British and other schools while their fathers served. This was designed in part to deter the Soviets but more to assure the Europeans that the U.S. would indeed sacrifice Chicago to save Bonn or Rome or wherever.
The task right now, the sending of planes and ships and some soldiers to Eastern Europe has been called by NATO the Reassurance Package. Are a few handfuls of fighter planes, six ships or so and a battalion of American soldiers (re-deployed from Italy to the Baltics and Poland) going to assuage the concerns of those closest to the bear and its victim? No. Not completely. But perhaps it is enough to remind East Europeans that they are on the other side of a shiny line from Ukraine and that line is between those who are members of NATO and those who are not.
I was asked on TV last night in Canada (the first time I got interrupted while being live on TV while being filmed at home via facetime/skype) about what difference does Canada make by sending six planes. To the Russians? None? To the East Europeans, it shows that NATO is more than the US, more than the US and Denmark but truly a transatlantic alliance. Not too shabby. But, yes, it is entirely symbolic. Canada now and into the future will only have enough air power to engage in symbolic stuff, as six planes can only make so much of a difference.