https://screenrant.com/what-happened-to-kittridge-after-mission-impossible/
Eugene Kittridge was the director of the IMF in the first Mission: Impossible movie in 1996, but after wrongly accusing Ethan Hunt, he disappeared.
Accusing the IMF agent that then went on to find the real mole, not to mention nail all of said mole's contacts, might have left him with a "quietly retire, please," from his superiors, no?
Why is the article asking about M:I7? By M:I2, Ethan is talking to Anthony Hopkins, not Kittridge, so Hopkins' character (name? what name?) seems to be in charge.
Either Kittridge moved up the ladder or retired somewhere between installments 1 and 2. If he retired, it could have been because he blew the mole hunt, or it could have just been his time to get out. I suppose he could have been killed, too. Is it that interesting?