Ireland had a strong interest in the post-colonial world, especially in the 1950's and 60's. Although it had no political colonies of its own, some recent research is starting to look at how Ireland created a "moral empire" in Africa through Christian proselytism. Check out Kevin O'Sullivan's book Ireland, Africa, and the End of Empire: Small State Identity in the Cold War, 1955-1975.

Ireland built or attempted to build ties with postcolonial nations, mostly in Africa, during this period. Ireland positioned itself as a natural friend of these nations, because it too had once been a British colony. It did this mostly through religious ties, because Irish missionaries were endemic in Africa and had made many converts (both Catholic and Protestant.)

There are lots of interesting Irish newspaper articles from this time criticizing European neocolonialism and the like. During the Biafran Civil War, Irish priests solicited for donations and food aid for starving people. And if you know any older Irish people, they are sure to remember the "black baby boxes" that were in many Irish shops, which encouraged donations to "adopt a black baby."

The thing is, Ireland's interest in Africa had many neo-colonial aspects in itself. Ireland got, or at least tried to get, real political and economic power in Europe through its actions in Africa. It was a way of making trade partners and of asserting power in the Cold War, because the Irish could flex their foreign policy muscles through foreign intervention. Irish soldiers performed some notable UN peacekeeping during this period. In a way, Ireland’s policy differed little from the great power blocs who waged proxy wars across the Third World in search of friendly regimes. Ireland hoped that this would allow it to play a greater role in European diplomacy, even though it lacked the firepower to be a serious Cold War contender. Other less powerful nations, like Canada and the Scandinavian states, had similar policies, playing the "fire-bucket brigade" of nations that would provide foreign aid and do UN duty as a way of asserting political might.

I honestly see Ireland's postcolonial ties as rather hypocritical. Although Ireland claimed to be the great friend of postcolonial nations (and this seems logical enough), its ties in Africa were built by piggy-backing on British imperialism. It was only British might and colonial outposts that ever allowed Irish priests to make so many converts.

Thus your question is a very pertinent one, and one that is starting to get some interest in academia. Scholars are starting to see imperialism (and neo-colonialism) less as a matter of nation-states (i.e. Britain had an empire and Ireland did not) but more as a complex web of social, economic, religious, and political ties. We need to do more research on how nations on the European periphery were enmeshed in and complicit in imperialism, even if they never had de jure empires.

Sorry if this answer is a bit muddled - this is a matter of strong personal interest to me. I am Irish and I believe my countrymen have a bad habit of patting themselves on the back when it comes to history. Great question!