Always looking for a fight
Margaret Thatcher loved nothing more than confrontation. Where she didn't meet it, she created it. The Falklands War was such an occasion.
She dived in purely for boosting her ego. At no stage were the Falkland islanders asked to become Argentineans. Even the recent, totally irrelevant, referendum only asked them whether they want to stay British. It had nothing to do with the territory. Thousands of British expatriates living in Thailand of course want to stay British, without Britain making claims on Thai territory.
The war itself ended fatally for 255 British soldiers - approximately one for every ten of the British shepherds on the islands. A high price to pay, but something that didn't seem to bother the un-turnable lady. Shame there weren't more Arthur Scargills around, who could have kept her busy without starting such a stupid war.