Okay, let's imagine you and your friend are playing pretend. You both want to defeat the bad guys in your game, but you both have different ways of doing it. You decide to work together even though you don't agree on everything. This is kind of like what co-belligerence is!
Co-belligerence happens when two or more groups or countries agree to work together to fight against a common enemy, even if they don't necessarily agree on everything else. It's like saying "I don't like you, but I don't like those bad guys even more, so let's team up for now."
For example, in World War II, the United States, the United Kingdom, and the Soviet Union were all fighting against Nazi Germany. Even though the US and the UK didn't agree with everything the Soviet Union was doing, they still worked together as co-belligerents to defeat the common enemy.
So, co-belligerence is like setting aside differences and working together for a common goal even if you don't agree on everything.