Original sentence: After a bitter struggle with the Metropolitan Special Branch MI5 took responsibility for leading the investigation of Irish republican attacks on England.It proved itself to be extremely successful in infiltrating the IRA, with Service operations (working closly with many police Special Branches) leading to 21 convictions for terrorist-related offences between 1992-1999
Edited sentence: After a bitter struggle with the Metropolitan Special Branch MI5 took responsibility for leading the investigation of Irish republican terrorist attacks on Great Britain.It proved itself to be extremely successful in infiltrating the IRA, with Service operations (working closly with many police Special Branches) leading to 21 convictions for terrorist-related offences between 1992 and 1999