F/A-22 IRST?

Having used an IRSTS in the F102A for over a year and a half (and
teaching its use to other pilots) I am continually amazed at the
refusal of the USAF and USN to employ some form of IRSTS in their
fighters. As simple and crude as the Deuce's IR system was, it still
added a whole new spectrum of attack modes to the weapons system.
Undetectable, unjammable, good against fighters in the weeds, line of
sight detection against head-on B58s at M 2.0 and picking up
afterburning 106s at 40 miles head-on. Surely a 21st century IRSTS
would be far superior to what we enjoyed back in the 60's. And the
Deuce's system weighed less than 50 pounds all told . . . the powers
that be might ask themselves why the Russians have IRSTS on all their
fighters.
Walt BJ