Did Benedict Arnold come out of retirement to advise the U.S. during the war of 1812?
A liability is still a liability, never mind the $10 million contract for memoirs. Clinton might be useful if we declare war on aspirin factories, but IMHO he should stay retired. If we HAVE TO take him at all, I would put him in a locked office with no radio, no TV, and no telephone, with a sign on the door that says "Don't Ask, Don't Tell".
I suppose we could use Carter to build temporary housing for our troops (I hear he swings a mean hammer), but he's more known for his foreign policy blunders than successes (Iranian hostage crisis and the aborted rescue attempt).
Let's send him to Cuba or China. He'd feel at home there.