[Renfrew]

“I can’t possibly see how an invasion by sea involving hundreds of transport vehicles and millions of troops could be carried out against a modern country armed with contemporary military technology”

Very good point. I don’t think any of the writers of these articles ever studied WWII in the Pacific. Amphibious landings are hard and impossible without air and naval superiority.

Since the 1940s defenses have improved (rockets, subs, drones), while amphibious landing craft remain the slow vulnerable targets they have always been.

[Antoninus]

Amphibious landings are hard and impossible without air and naval superiority.

True--during a declared war where the side under attack is waiting for the attack to come. When the invasion fleet lands unannounced before war is declared---that's a whole different scenario.

[Tallguy]

https://www.thehistorypress.co.uk/articles/exercise-tiger-d-day-training-at-slapton-sands/

Witness what a few German E-boats were able to do when they happened on a bunch of LST’s making a training landing shortly before D-Day.