If efficient equals, cost effective then UK should win. I know it was a long time ago and may well have changed now, but when I was deployed I didn't get any danger money, hostile fire money or other extras for having the pleasure of being shot at. It was deemed as being expected when you joined.
Well that is what is good about the US military. It takes care of its soldiers. Most of those allowances I recieved whether I was deployed or not. The Army paid the rent on my house, they gave me COLA to adjust to the high cost of living in Germany, they gave me Seperate Rations to buy food for my family and flight pay I recieved regardless if I was deployed or not because that was my job, I flew every day.
The only extra allowances for being deployed were the Hostile Fire Pay and the Family Seperation Pay.
The only real good thing was that it was tax free and there was nothign to spend money on in the desert so you save a butt load of money.