1,500 French and British troops originally landed in Arkhangelsk 14,378 British troops in North Russia 1,800 British troops in Siberia 50,000 Romanian troops belonging to the 6th Romanian Corps under General Ioan Istrate, in Bessarabia. 23,351 Greeks, who withdrew after three months (part of I Army Corps under Maj. Gen. Konstantinos Nider, comprising 2nd and 13th Infantry Divisions, in the Crimea, and around Odessa and Kherson) 15,000 French also in the Southern Russia Intervention 40,000 British troops in the Caucasus region by January 1919 13,000 Americans (in the Arkhangelsk and Vladivostok regions) 11,500 Estonians in northwestern Russia 2,500 Italians in the Arkhangelsk region and Siberia 1,300 Italians in the Murmansk region. 150 Australians (mostly in the Arkhangelsk regions) 950 British troops in Trans-Caspia 70,000+ Japanese soldiers in the Eastern region 4,192 Canadians in Siberia, 600 Canadians in Arkhangelsk
https://en.wikipedia.org/wiki/Allied_intervention_in_the_Rus...
That German Empire fell after WWI, and was replaced by the Weimar Republic which itself did little against the Reds itself but a large assortment of now unemployed German soldiers did join the fight.
The Allied Powers on the other hand, formally supported the White's and launched invasions into Russia. No matter how active they actually were in the war, the hostility would have prevented any Soviet interference in Ireland.
Not sure that was true. Europe was pretty busy with the aftermath of WWI (and to a large extent, Germany supported Lenin getting back into Russia in the hopes that he would instigate a revolution there that would take Russia out of the war). US had supported Kerensky's government, was anti-Bolshevik and withheld diplomatic recognition until 1933, but was hardly "at war" with the USSR.