> helping Saudi Arabia in its fight against Houthis in Yemen at the invitation of the Yemeni government;

And by the Yemeni government you mean of course the Saudi puppet with literally no legitimacy what so ever. Even the very, very little legitimacy he had as the Vice-President of the former dictator, that dictator had already been rejected and disposed.

Of course they tired a totally unconstitutional Napoleonic style election to give justification for their actions. But it speaks volumes that 'the Yemini government' by now is a guy sitting in a hotel in Saudi Arabia having been kicked out repeatedly from multiple cities in Yemen because not even the supposed allies of the Saudi coalitions want him.

And they are both blockading Yemen economically and had actual US troupes fly over Yemen. And helping in lots of other ways.

Its in my opinion as despicable an set of action as any invasion.

> special forces fighting Daesh on Syrian soil

The total of American presents in Syria is far more then what we would usually special forces. I guess you can just define anything as 'special' if you want to.

In reality they are occupying large parts of Syria against the will of the internationally recognized government long after even the flimsy excuse of an emergency situation is no longer valid.

> When people think of "a military invasion," the term certainly has a connotation, and maybe a denotation, of heavy armor and infantry divisions rolling in for the purpose of occupation.

Imperialism is not just innovation. The British Empire didn't invade a lot of places that it considered essentially or explicitly part of the empire.

So instead of quibbling about what constitutes an 'invasion' lets just recognize the essential reality.