The EU did not exist in 1982. Its predecessor, the EEC, was more like a trade-bloc and lacked any sort of foreign-policy cooperation. The creation of the EU in 1993 was supposed to improve this state of things, and it did - in a lot of situations, the EU now speaks with one (bigger) voice. It might not be as loud as some would like (partially because the UK pushed hard to water down anything defence-related, for fear it would supercede the NATO setup they prefer), but it's there.

Similar considerations apply for the Balkan wars, that started before the EU existed.

On Ukraine: it's not like the US did anything either. Ukraine is not an EU member. The responsibility for guaranteeing Crimea's security, under the Budapest memorandum, sat squarely with the US and... the UK.