You're downvoted but I don't think you're wrong. In general it seems to be the case that if you're waging a war and you're not getting completely crushed the electorate (or at least the "undecided" voters") tends to rally around whoever happens to be in charge. And indeed I think it's fairly safe to say that most agree that Thatcher benefitted electorally from a strong response to the invasion.

I should add that as a Scot I'm definitely not a fan of hers (you just grow up there knowing "Thatcher Bad") but I'm not quite at "put a stake through her heart and garlic round her neck"[0] :)

[0] - https://twitter.com/halaljew/status/1294414600566382598