All the EU (in fact the entire free world including Latin America and Africa) need not spend a dime in having their own military.
They know that if the slightest thing happens against them militarily, the US Military will jump in, on the US taxpayers’ dime.
Apart from all the US dimes and dollars that went into the collecting tins in the States for Irish terrorists to kill British soldiers.
If you think Britain relies or has relied on your military, your ignorance is off the chart. I am sure 99% of your fellow Americans will think you are talking rot.