Can I sue the government or the chemical companies?

No. Title 38 of the United States Code prohibits veterans from suing the government for injuries suffered while in the military. A class action suit was filed in behalf of veterans in 1979 against the chemical companies and settled out of court. The final funds in this legal action were distributed by 1992. Additional attempts to sue the manufacturers have been attempted, and have been prohibited by the courts. The most strongly fought of these legal battles, Ivy vs. Diamond Shamrock was supported in behalf of the plaintiff by attorney generals in all fifty states, the Supreme Court, however, refused to hear the arguments and that case ended in 1992. In the parlance of the court, the issue is "res judicata" or "the matter is settled".