From: US Midwest
Bottom line is, they always do whatever screws you over the worst. Recently, I was forcing my way into the med with the allies and had to fight my way through the Italian navy supported by several German subs. In the narrow passage, my opponent had his subs directly in front of his surface fleet, preventing my fleet from getting access to his surface combatants. I had to get the subs to move, so I attacked them with destroyers, thinking they would dive giving me a clear path to his ships. Wrong. They took attack after attack, taking a point or two of damage each time, but never diving. They remained in place blocking my navy for several turns, while I got beat up by his air force. I eventually got through, but the delay had devastating consequences in the long run.
Just goes to show...
Lock up your wife and children now,
It's time to wield the blade..