It has taken several years, but it seems that the seed planted by the Lisbon Treaty has finally started to sprout.
www.irishtimes.com/news/politics/varadkar-defends-neutrality-as-eu-steps-up-co-operation-on-defence-1.3129961
Fine Gael caught in a cleft stick due to their being the most pro-EU party ever conceived (besides maybe Macron's EM or Merkel's CDU) and defending the holiest of holy Irish international issues (namely neutrality).
In order to appease both camps Leo seems to be blurring the lines about what is a defensive alliance (or at least picking out a minor aspect of proposed legislation)
Having said that, co-operation around security and defence is changing. The threats that we face in the world are less about wars between countries, and more about threats created by terrorism, by extremism, and by cyber attacks for example.
...
And those areas are not areas in which we should be neutral. We should be very much involved in working with European partners to prevent cyber attacks to manage migration and to stand against terrorism.
Small acorns, mighty oaks.