What was to be broken up

In gross GDP, China will almost definitely surpass the United States as the nation with the largest economy in the next five years, bu the combined output of the European Union will still surpass either of these.  So to an outside observer it is puzzling to see Britain distance itself further and further from the continent that absorbs half of its exports (James Bond and Downton Abbey are among the last remaining British exports to the United States).  But Britain is behaving like many great ladies in a relationship where She always thought She was out of the other's league. 

Continental Europe is not as financially fit as He once was and there seems to be no end to His problems, and the classic move is to focus on the delta from the good times and ignore that on the whole She is still better off with Him than without. 

In Her mind that is still reeling from recent sleights where she has had to pick up the check for a few meals when his card was declined, and embarrassed that they won't be able to buy the new car they had been looking at, she imagines a future where He understands why She is leaving Him, and they will still be friends with most of the same benefits at her convenience.  After all, who could resist her?  But She underestimates the bitterness of a scorned lover. 

She thinks that their mutual friends, the car makers and financial services companies with headquarters in her backyard will definitely side with her in the breakup, but gradually they will drift away especially as He recovers.  And once He does (and He definitely will) and is back in great shape and She is feeling the sting of making it on Her own, He will take her back.  But this is far from assured.  

 If She is going to leave it had better be because She wants autonomy at almost any cost and is willing to pay the steepest of financial and political prices for it.