Earlier quoted context omitted.
Europe has a huge coastline, it's impossible to blockade. If war breaks out, it's better to shift workers from agriculture to war-related production, and import food from places that are not at war, such as South America. Food produced in Europe is basically a luxury. For every kilogram of beef produced in Denmark, you can buy 2.5 kg of Argentinian beef.
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.
Note that I actually agree with your position but this is an interesting discussion on a topic I hadn't thought about deeply enough!