### Clue: Orchestrated UN's clash with second German political union (9)
### Answer: ANSCHLUSS 
 ### Explanation: Orchestrated UN's clash with second German political union (9)
*(un's clash) + **S**(econd) 
*Anschluss, the German word for "addition" or "connection" is now synonymous with the political union between Hitler's Germany and Austria in 1938.