This paper examines the use of the term 'territorial integrity', a term with two interlinked and usually compatible meanings. The first is that states should not seek to promote border changes or secessionist movements within other states, or attempt to seize territory by force. The second meaning is the standard idea that within its own borders, within its territory, a state is sovereign. The second of these two meanings has come under increased pressure in recent years, in part in relation to international intervention for 'humanitarian' reasons, and even more so since September 11 2001. And yet the other meaning is being stressed even more explicitly, often at the same time and in the same places that the second meaning is being challenged. This paper considers various historical and contemporary examples, and suggests that the two meanings of territorial integrity are increasingly in tension.