If the US wants to land 2 infantry in the Phillipines with only a transport and the Japanese only have a sub in the sea zone, I cannot land? right?
You used ‘unescorted’ as the operative word. An unescorted transport cannot amphibious assault a sea zone with an enemy sub.
What if I use a destroyer as an escort… do I need to attack the sub to land? Can I just land without sea combat? What if the sub destroys my destroyer, can I still land?