The United States and other NATO states often ignore this sensitive issue, likely because of potential effects on their war strategy in Afghanistan. Their involvement could strain relations and jeopardize their own national interests in the area. This came after the November 2011 NATO bombing in which 24 Pakistani soldiers were killed. In response to that incident, Pakistan decided to cut off all NATO supply lines as well as boost border security by installing anti-aircraft guns and radars to monitor air activity. Regarding the Durand Line, some rival maps are said to display discrepancies of as much as five kilometres.