If I were President, and I faced a shortage of personnel to infiltrate those 37 or 60 or however many countries that have active terrorist cells in them, then I would certainly look to the pool of those who are retired from active service. Now, I don't know that a shortage exists. I rather doubt it given the number of people who are jumping at the chance to do something here to help. But let's assume that you are right, and there is a shortage. One option would be Marque and Reprisal. That creates a bunch of bounty-hunters doing who knows what. The other option would be to actively recruit those same people to join the fight on behalf of the government. That way they could be given classified information, assistance, logistical support and it could be done in a coordinated fashion. The CIA or FBI don't want Rambo busting into a camp when they're staking out a meeting that is scheduled for two hours later. So, if I were President, I'd veto any Marque and Reprisal bill that reached my desk, and bring these folks back into service as needed. Marque and Reprisal pre-dates intelligence agencies and official clandestine operations. It's now a relic of a less-complicated time.The "Weekend Rambo" characterization just doesn't hold water.
These "Weekend Rambos", let's bear in mind, are guys who have already done their twenty for God and Country, behind enemy lines and over cover of night -- not wet-behind-the-ears young college grads fresh out of Langley flying an Intel desk for the first time.
There's no need to go back to 1790 for a contrast here. Historically, in comparison between Ofiicial Government military action, and private "Yahoos", those "Yahoos" come off very well -- Very well indeed.
...as radical as the idea of resurrecting Marques and Reprisals might seem to Non-Libertarians (who tend to think in terms of purely governmental solutions), the facts of history are pretty straightforward: In 1979, American citizens were being held hostage by the radicalized, quasi-terrorist Revolutionary Islamic government of Iran. The US Government under Carter conceived, as you'll recall, a search-and-rescue operation termed "Desert One" which turned into an absolute fiasco -- a miserable failure. At the same time, Ross Perot contracted a private mercenary operation headed by former Green Beret "Bull" Simons to rescue EDS employees being held by Iran. The Private Sector action, while a little messy in execution, was (by contrast) a complete success.
Apples and oranges. Perot was going after his own employees and Carter was trying to rescue Embassy personnel. Perot, you notice, was motivated to do his thing even in the absence of a Marque and Reprisal bill.
What you are advocating is motivating people to do actions in competition with US clandestine operations. If there are Americans who have skills in those areas, they should contact the government and offer those skills. Being a retired Marine is not sufficient qualification, IMHO.
Nevertheless, there is nothing preventing any American from boarding a plane to Pakistan tomorrow, where there are no shortage of arms for sale. A reward is already offered, so get your friends and go.