collaborate = 共同努力, 合力, 攜手 (both have a common goal - 雙方利益)
cooperate = 配合
cooperate with someone: 配合某人 (未必互相利益)
When the police catch a criminal, and they interrogate him, if the criminal does not respond, he is "refusing to cooperate". But if he answers the police's question, he is cooperating with them, but not collaborating with them. To collaborate with the police, the criminal would need to help them catch more criminals.
Collaborate means there is a common goal.
Cooperation does not necessarily mean the people are working together. Only that at least one is helping another....
He cooperated with the other's request. (one is helping the other only).
Cooperate = to do something to be in harmony,
collaborate = working on something together
In Andrew's example, "to cooperate with the enemy" could mean to surrender if they were going to shoot you. you cooperate with them if they catch you and you accept to be taken prisoner instead of fight.
but to "to collaborate with the enemy" would mean to help them fight your own country