By joining forces with one enemy to eliminate another is a catch 22 but it may be a necessary action. When a bad character kills another bad character it doesn't seem as bad as when a good guy kills. if this tends to be the only way to stop the ultimate enemy than it may be a needed sacrifice.
I thought that was standard practice for all countries. I think we should continue to do that. Pooling resources is always a good thing, but let's not use it as a smokescreen to do illegal or immoral things. Hopefully partnerships like that will continue to keep people honest. We will have to see.
There is a saying the enemy of my enemy is my friend. Sometimes even if we have had bad feelings in the past with say a certain country if we face a common enemy it can help bring us together. Is it always wise to trust those we have been enemies with in the past maybe not but it may come down to putting those differences aside to face a common enemy.
If the United States forms allegiances with known enemies, it should be for the sake of reconciliation and world peace, not in order to take down other enemies that are held in common. Unification with other enemies doesn't mean that problems are solved. Future conflicts with enemies are inevitable even if we form alliances with them now.