The question is the answer. Trump weakened NATO. He pulled us out of the blue skies treaty, which was designed to watch Soviet military activity along the Ukranian border. Biden immediately pledged to back NATO and work against Russian aggression. Russia knew they had a limited time and they couldn't afford for Ukraine to be allowed to join NATO. So they attacked. They just underestimated the will of the Ukranians and also the will of some of the NATO members to immediately supply things like Javelins and anti-air assets. | 
the last hurrah for the farmer
