Is that photo in Zimbabwe (stealing property from Whites)=?
The picture in #2 illustrates your point just fine.
The Geneva Convention and the Law of Armed Conflict that nations recognize state that soldiers must wear a common and recognized uniform to distinguish them as soldiers fighting for their nation.
If they are not wearing said uniform, they can be treated as spies.
This is the same problem we have with Islamic terrorists held at Gitmo, who are not even entitled to the privileges of being a prisoner of war through the Geneva Convention, but through their ACLU lawyers and our stupid SCOTUS can now claim the same rights as American citizens.