And this is why analogies are bad.
A few important details:
1) The EU is not a country.
2) The one-country veto already has limited applications within the context of the EU. Foreign policy is one of the most important, but most EU laws start from the Commission and go through Parliament instead where they pass by a simple majority.
3) What von der Leyen is in effect asking for is for EU member nations, who are sovereign and with each having their own foreign policy, to subordinate their foreign policy to the EU’s foreign policy. That is a massive power shift from the members to the EU Commission.