Since you've posted under the forum for Rick Steves tours, I'll tell you none of his tours cover all 3 countries.
I also expect you didn't really mean you wanted to take one of his tours, so I'd default to the advice given.
You've also listed 3 countries and you've been to 1 city in one of the countries. In 2 weeks you could do Paris, Madrid and Rome flying between them and booking your airline tickets as open jaw - in to Paris and out of Rome. You will lose a 1/2 a day moving between locations. Your beginning 2 days are used up with travel from the US (assuming you are coming from the US) and the last day will have no time to tour, so you've really got 11 full days - 4 Paris, 3 Madrid, 4 Rome. Your arrival day doesn't count for much but you'd have that extra night in Paris.
That might be a trip you'd enjoy altho it would be too much long-distance travel for me!