is moving more troops and weapons like f-35s and apache attack helicopters toward nato-allied countries in eastern europe and the baltics. biden is adamant that u.s. troops will not fight in the ukraine. so what does this added level of force do? >> well, provides -- obviously if it's not -- deterrence gives you two things. one is the force that you are trying to put in place will deter your opponent because of its capabilities, its size, its strength and your willingness to use it. the second thing of deterrence is if that incredible step doesn't work you've got a capability to start killing a bunch of bad guys. you can crush some people. so increasing that presence bolsters nato. it makes nato feel like we are going to be unified in this. p and putin wants to try to fracture that alliance. but when you look at this map, you realize that nato over the course of the last 20-plus years has expanded to the east and that's what has putin upset and now has him talking about reclaiming ukraine.