in 2010 the uk government's strategic defence and security review announced its intention to "withdraw the sentinel airborne ground surveillance aircraft once it is no longer required to support operations in afghanistan." sentinel has supported the british army in afghanistan. its role above libya in 2011 was described as "pivotal" by the head of the raf. in february 2012 it was announced that sentinel would be offered as the uk contribution to nato's alliance ground surveillance (ags) collaboration, complementing nato rq-4 global hawks and french heron tps.