... brick to fall from the wall.

Other EU members are starting to consider exit and what stops them is the cost and the example of the UK which was a negative example of the consequences of exit from the EU.

The US has been fomenting the EU breakup for decades. The US doesn't want a united and strong Europe. The US wants a weak, fractious divided Europe because it is easier to bully small countries than a huge united block of countries.

The US doesn't want any countries to unite.