Abstract
This chapter asks: under what circumstances can force be used to put right contested issues of territory? Not every territorial injustice justifies the use of force, but some do. It examines the standard case, which is the right of the state to defend itself, and particularly to defend its territory, then moves to more controversial situations involving either the defence or breach of territorial integrity. The book’s overall theory is considered in the light of what it says about: military force used to regain territory or territorial rights; annexing territory that contains a majority of people who identify with the annexing state; force used by secessionists to break up an existing territorial state; force used by a majority against secessionists; and external intervention in contentious cases.