BELFAST (Reuters) – The United Kingdom lowered its Northern Ireland-related terrorism threat level for the first time in more than a decade on Tuesday, with police saying operations against Irish nationalist militants were making attacks less likely. The threat in the region from domestic groups has been lowered to “substantial” from “severe”, according to an independent assessment by the MI5 domestic spy service, the British government’s minister for Northern Ireland Brandon Lewis said in a statement. That means at attack is considered “likely” rather than “highly likely.” It is the first tim…