LAS VEGAS — The contractors who run the Nevada National Security Site, formerly the Nevada Test Site, have been scrambling to find new missions to keep the facility alive. And with its wide open spaces and secure borders, it’s the perfect place for covert training.

But how would taxpayers feel about using public dollars to train foreign insurgents, including some who are officially considered to be terrorists?

It’s never really clear how these things can turn out, and sometimes such operations can backfire. For example, in the mid-80s, America trained and armed Afghan rebels to fight against the Russian army. Those same Afghans later joined the Taliban and have used the training we gave them to kill American soldiers.