The fact that invasion is not being advocated does not mean it won't happen in time. The relevant expression is "mission drift". For that matter the fact that invasion is not being publicly advocated, and is being publicly disavowed does not actually mean that it may not in fact be anticipated. "Truth is the first casualty of war".

Moreover "invasion" as such is just a tactic. Germany never invaded Britain. Nor for that matter did Japan invade America or America invade Japan.

I note that the Daily Mirror reported yesterday that there were SAS forces actually in Syria already. Perhaps it was true, it wouldn't be the least bit surprising.