The remnants of the IRA, which had split several times into ever smaller groupings since 1922, embarked on a bombing campaign in Britain (see Sabotage Campaign (IRA)) and some attacks in Northern Ireland (see Northern Campaign), intended to force a British withdrawal from Northern Ireland. Some of its leadership, notably Seán Russell, sought help from Nazi Germany for this project. De Valera, considering this activity a threat to Irish neutrality and therefore to the state's vital interests, interned all active IRA members and executed several. Another was hanged in Northern Ireland for shooting a policeman.