After September 11, 2001, the CIA, and other American intelligence agencies, suddenly had a lot more work to do. One problem was intelligence analysts. This was solved by having existing analysts work more hours each week, and transferring analysts from other departments to anti-terrorism operations. The areas that gave up the most people were global political, economic and military trends analysts, plus many from counternarcotics, counterintelligence and the weapons proliferation. Currently, the CIA has about a thousand anti-terrorism analysts. This is more than five times what they had before September 11, 2001. But there was also a need for more people out in the field. Here the CIA hired a lot of it's own retirees, as well as more recently retired military people (especially Army Special Forces and Marines who had developed a taste for special operations.) The CIA has long recruited recently retired army and marine NCOs and officers for their field operations. These men (and some women) are still relatively young (late 30s to early 40s), in good physical shape and have a track record of working in a large military organization. Some of them, especially Special Forces troops, have language and other skills that are of immediate use to the CIA. The rest are sent into a training program, which includes a lot of on-the-job training. Language skills (Arabic, plus all the languages found in places like Afghanistan, Pakistan and Somalia) are being acquired using contractor instructors. Intense language immersion courses can provide a minimal "starter" vocabulary in a few weeks. The rest can be picked up in the field. 

Since it's a wartime operation, recruiting standards are not as strict. This is not necessarily a bad thing. In peacetime, CIA bureaucrats are reluctant to take on someone who appears really good, but perhaps a bit to imaginative and "unpredictable." In peacetime, "better safe than sorry" is the byword. When there's a war on, you take more chances, and end up getting more daring people out into the field.