If you aren't missing limbs or squirting blood, it is really difficult to get anyone to believe you're "wounded".

Radiation poisoning? Well, that's bad cancer in 10+ years.

Sarin? Are you sure you weren't sick before you went there? Are you sure you're not shirking? You're just trying to get money out of the government.

Remember how long and hard people had to fight to get "Gulf War Syndrome" recognized?

Those casualties won't be recognized on the battlefield. Or even for years after coming back.