operation diesel was a raid by 700 british troops from the royal marines 45 commando , 42 commando , and the 3 commando brigade 's reconnaissance force , as well as armoured infantry and close reconnaissance from 1st battalion princess of wales 's royal regiment ( 1 unk ) on a taliban drug factory and arms stronghold in the upper sangin valley in helmand province , afghanistan on february 7 , 2009 .