What is the ruling on men wearing trousers that resemble military uniform, and is that considered imitating disbelievers?

The forbidden imitation of disbelievers is that which is exclusive to them. As for what has become widespread among Muslims and is not distinctive to disbelievers, it is not among the forbidden imitations, even if its origin was from them. What is meant by "exclusive to disbelievers" is for a Muslim to dress in their attire such that an observer would say, "This person is one of them." As for what Muslims and disbelievers share, such as wearing trousers, it is not considered imitation.