This is simply not correct, and even Gorbachev has confirmed this. There has never been any agreement stating that NATO is not allowed to accept new members in any particular direction. There were statements made by western politicians but never any pen to paper. The sovereign states that have joined NATO have not done so because of some US campaign or persuasion, but by their own free will. Your statement is indirectly saying that these countries are too dumb to decide for themselves, it's incredibly condescending.