Er , right . The rather notoriously nonmilitaryminded armed forces of the rest of the EU decide to invade the two nuclear powers . I think I ' m right in saying that they also have the largest and most effective conventional militaries in Western Europe . You don ' t get to be a leading politician in the EU or a military leader by being foolish , and invading either country would be exactly that . Assume for a moment , that neglecting even the remotest credibility , Brussels tried this . With respect to the UK the EU troops would be attacked as they attempted to cross the Channel . British diplomats would attempt to defuse the situation in Brussels , but carrying the overt threat that failure to withdraw will see the use of conventional cruise missiles in the first offensive move , aimed at targets such as the European Parliament . France would probably have a less measured response , due to a history of invasion by Germany . They would quite possibly move directly to threatening a nuclear response .