

They still wont be safe. This sets in motion a chain of events that probably ends in WWIII, which is something they have known all along. They are also probably too late. The time to start building a solid military to defend you today was about two decades ago.
Yes, but they both only want these things as means to an end. In the long run they both have dreams of becoming imperial super powers. They can cooperate for now, but they both know its an alliance of convenience.