This is an old story. The 2015 Irish Defence white paper included:
Air Combat
The existing Pilatus PC9 aircraft provide a very limited air to air and air to ground capacity and these are due for replacement in 2025. The development of a more capable air combat/intercept capability will be considered as part of the White Paper update
In the last 20 years Irish defence spending has fallen dramatically in GDP terms from 0.8% to 0.27% mainly as a reflection of increased GDP as in cash terms it has nearly doubled to EUR1.08bn. Were it a Scandinavian or Central/Eastern European country of similar size I'm sure it would have had a modern(-ish) air defence capability. Clearly Ireland's geographical position isolates its from any direct state level threat and enables it to leverage RAF QRA. However, UK military involvement in Irish air space obviously carries historical/political baggage. The acquisition of an effective radar and involvement in the management of interception by friendly air arms would seem the obvious solution. To avoid the politically unacceptable NATO label, an EU based defence arrangement would have made sense if the UK was still a member. It will be interesting to see what impact, if any, the new Fianna Fáil–Fine Gael–Green Party government has on Defence spending and priorities.
I am unfamiliar with the intricacies of Irish Defence politics but the Equipment Development Plan (EDP) is part of the first iteration of a recently adopted 6-yearly SDSR type process. The process of evaluating capability gaps appears to be eminently sensible. A conditional commitment to acquiring a Primary AD Radar was made in the 2015 Defence White Paper "Should additional funding, beyond that required to maintain existing capabilities become available, the development of a radar surveillance capability is a priority for the Air Corps." Although the White Paper stated the PC-9s were due for replacement in 2025, this isn't mentioned in the 2019 Update, however, the EDP lists upgrades between 2022-24 as being in the "Major platforms in planning" category.
Personally, I find how other countries do things interesting - apologies for the lack of brevity to those who don't.
The EDP is comprehensive in its scope.
The EDP is based on a rigorous prioritised examination of the range of equipment requirements to deliver on roles and associated capabilities. Prioritisation must take account of the immediacy of any operational demand as well as planning, specification, procurement, production and delivery time-frames and relevant resourcing. At any one time, there will be a balance of what is feasible within available funding and what is needed taking account of equipment life-cycles and the needs of on-going and contingent requirements.
An EDP (Equipment Development Plan) is understood to involve more than an inventory of acquisitions. It comprehends the total process associated with achieving outcomes which supply the equipment component of military capability. Thus, it is a “development” plan rather than merely a plan. This is given substance by the life-cycle process governing equipment from initial planning through to delivery into, and then sustained, in service. In all cases, the basics are identification of an existing or future capability gap; consideration of a possible appropriate equipment related response; assessment of options and determination of a recommended approach, followed by allocation of resources, procurement and acceptance into service. ... Contingent requirements also include those which are less immediately likely but which, particularly at the more extreme end of the defence spectrum, provision must be made.
Future programmes at pre planning stage
Beyond the very significant range of projects already underway or in existing planning streams, the EDP highlights others that are expected to progress in future phases of the plan. This is not an exhaustive list but gives an indication of the scale and range of programmes that will enter planning. At this stage there is not a definite commitment to pursue, or an associated time-frame, for these. These include a primary radar system, air combat interceptor, replacement of the two Coastal Patrol vessels, acquisition of diver based mine counter-measures and counter improvised explosive device equipment, field catering equipment, various vehicles such as replacement mini-buses, military trailers and an armoured ambulance as well as various surveillance and explosive ordnance disposal equipment.
A number of weapon systems are also earmarked in this category of pre-planning such as upgrade of the 105mm light artillery gun, the 60mm mortar, under-barrel Grenade Launcher M203 Replacement, RBS 70 MANPAD replacement Programme, Steyr Rifle - Mod 14 Upgrade - Under Barrel Rail and Foregrip.