According to the latest WikiLeaks drop, the DEA is more than just a drug enforcement agency—it's become a kind of alternative diplomacy/intelligence agency. Take away the drug war and you take away the DEA's cover:

Cables describing the drug war do not offer significant disclosures. Rather, it is the details that add up to a clearer picture of the corrupting influence of big traffickers, the tricky game of establishing which foreign officials are controlled by drug lords, and the story of how an entrepreneurial agency operating in the shadows of the FBI has become more than a drug agency.

The DEA now has 87 offices in 63 countries and close partnerships with governments that keep the CIA at arm's length.