Australia was recently involved in negotiations with Russia to bring a prisoner of war home. He had no military experience in Australia but went to Ukraine to help defend them against attack. Australian military is not involved but we do support Ukraine with weapons, training etc.
Cuba is USA neighbour that has been oppressed by USA for many decades. It is natural their people would join a war against its oppressor.
If USA had lifted the oppression earlier, maybe they wouldn't be there. They'd certainly have fewer motivations.
Cuba has just been hit with one of the worst cyclones ever seen in the region. They need medical equipment, food, etc etc
UNGA voted 163 in favour, 7 against, 12 abstained.
I pray USA lifts its restrictions.