This is basically a copy of the Bravo Two Zero (the Marines call-sign is Bravo Two One), mission from The Gulf War, it was undertaken by the British SAS, the 200 mile walk was undertaken by "Chris Ryan" (real name unknown), 3 were killed and 4 were captured by the Iraqis.
The admiral indicates that Marine Force Recon is a special operations unit. Marine Force Recon is designated special operations capable which is unique to Marine units. That designation means that the units can be tasked with what would be unconventional actions, but are not part of the special operations command that Seals, Delta, and other Special Operations units are used for.
Chris Ryan's real name is "Colin Armstrong".