You have the French blocking the English get an into the European Union

The British destroying the French fleet during world War 2

And in the interim of both world wars them both undermining each other's position in the middle East

Then you got the issue over brexit and the migrant crisis

That just the recent stuff

To be honest it goes back to the 1150s when will in the conqueror was still just Duke of Normandy fighting a war

Against Henri I of France and annihilating half of his army

If you combined the history of conflict and of bad relations it adds up over time

It's why the USA could be the protector of international trade because it doesn't have bad blood with other nations

For the USA it's more psychological trauma