While Europe has a long coastline, there are only a given number of ports capable of the high thoroughput needed to feed Europe’s population. Blockade those and the entrance to the Baltic and Mediterranean, and most of your work is done. Moreover, in a shooting war, merchant ships from other global regions attempting to supply Europe would be targeted.
> Moreover, in a shooting war, merchant ships from other global regions attempting to supply Europe would be targeted.
This happened before, twice. The solution was convoys, it worked both times.
The convoys barely worked. Parts of Europe were desperately short of food for several years. And the non-Axis countries couldn't manage to defeat the blockade on their own: they needed help from the USA to accomplish anything.
It didn't work for Japan though. The US could've kept Japan impotent and hungry indefinitely without invading or nuking it. The main reason for nuking it was to get it to surrender before Stalin could enter the fight and take part of Japan.
Who is this hypothetical battle to be fought against? Surely anyone with sufficient power to mount a blockade has nuclear missiles and at that point it's kind of moot...
Note that I actually agree with your position but this is an interesting discussion on a topic I hadn't thought about deeply enough!