Why would the IAC need fighters? The RAF or USAF would protect Ireland against attack, they have been doing it for 60 years. What would the IAC of used against an attack by the Soviets in say, 1985. A Fouga Magister?
The IAC should buy some old Mig-21s, L-39s or whatever is faster than an airliner, just to have something to intercept an aircraft. Have five of them with one of them on a 15 minute alert. This way you could say Ireland is protecting its own airspace. Or buy some SAMs. The IAC would never be able to stop a determined attack by say the RAF or anybody for that matter. So the Irish military should just continue to equip thier Army with the latest toys, since that is its best deterent. The IAC should stick to light attack, Surv. and transport.