Jesus wept!
Having grown up and lived through the Northern Ireland Troubles, let me explain the differences between us and Ukraine.
Northern Ireland wasn't invaded at all. The Northern Ireland Government in 1969 requested the aid of the British Army as the RUC was close to collapse due to exhaustion.
Ukraine, on the other hand, WAS invaded by an aggressive country with tanks, hundreds of thousands of soldiers, missiles launched at Ukrainian territory including civilians.
Already that highlights how utterly ridiculous it was for you to attempt to compare Northern Ireland's Troubles with the war in Ukraine.
Northern Ireland's people weren't successfully terrorised by Republican and Loyalist terrorists in any serious numbers. Over 38 years, a little over 4,000 people died. Hence, we and the Security Forces could easily absorb their campaign of murder.
Ukraine, in sharp contrast, has a much higher death toll in less than a year according to the UN:
"From 24 February to 4 December 2022, OHCHR recorded 17,181 civilian casualties in Ukraine: 6,702 killed and 10,479 injured."
Northern Ireland was NOT a war by any means. It was a low level terrorist murderous campaign that ultimately failed.
Ukraine IS a war by every measure going.
In Northern Ireland, we could go to school and people could go to work without much problem. In Ukraine, normal life cannot go on due to the aggression of Russia and their missiles, for example.
We could live a normal life in Northern Ireland for the most part.
Given all the above, we in Northern Ireland could have referendums in 1973 and 1998 where people could cast their vote unmolested in the secrecy of the ballot box. People very largely stayed where they always lived with small numbers of exceptions and even then they almost all stayed in Northern Ireland. My own family have lived in a town in North Down for at least 150 years.
Compare this with the sight of Ukrainians leaving for numerous European countries due to the devastation of the war Russia forced onto them.
It's painfully obvious why a referendum in Ukraine on territorial integrity and independence could NOT take place in a way that satisfies international law.
Referendums in Northern Ireland were and are fully compliant with international law.
Please, don't make such ridiculous, baseless and sensationalist comparisons between the Northern Ireland Troubles and the war in Ukraine as forced on the people by Putin's Russia.
It's offensive to us and the Ukrainians. Not to mention utterly bollocks!