Today marks the 70th anniversary of the Soviet invasion of Poland. That's not such a great time to cancel the missile defense shield for Europe. Especially since it was to include Poland and the cancellation is seen as a capitulation to Putin.
Even worse is that this happens just a couple of weeks after we snubbed the Poles at the commemoration of the start of World War Two.
UPDATE: Good posts from Neo-neocon and Fausta's blog:
UPDATE2: Great article from The Weekly Standard: