Ukraine wanted to join NATO, remember?
2. Most of Eastern Europe has been in NATO for over 20 years and has not seen any permanent stationing of "NATO troops", whatever that means. And the forces that were in Western Europe have seen dramatic decrease since the 1980s, around 5-10x across all key categories (personnel, weapons, etc). The US military is currently undergoing a review with the goal of making further reductions of their presence in Europe.