212. the USMC fly the TAV-8B, the T-2 Um is referring to was the Rockwell T-2 Buckeye, it was the US NAVY basic jet trainer and it had two engines.
The whole US NAVY training pipeline is now covered by the T-45, another Brit design.
By the way, Harriers T.2 and 4 have been gone for quite some time now, I believe the only two seater left is now the GR.9.