We cooperate with Russia because we need them to ferry
our astronauts back and forth from the ISS. Why? Because we would rather add another 70 billion dollars to an already bloated military budget, than spend what is necessary to do the transport ourselves.
But Russia is otherwise our enemy? Really? Why does our government need enemies to fight, except for profit? Don't get me started on the Middle East.
China makes too much of our stuff, so we don't want to upset them too much.