However, I can see why there would be resentment towards the Irish actions (or non-actions) during WWII, which seem to an outside observer to be incredibly stubborn. Surely, they could have joined the Allies once the threat of German invasion was neutralized?
The fact that a neutral State uses force to repel attempts to violate
its neutrality cannot be regarded as a hostile act.
Neutral States receiving troops belonging to the belligerent armies on
their territory must intern them. It would be a violation of the duty of
non-participation if the neutral State permitted such troops to take part
again in hostilities.