UPI has compiled a list of the nationalities of prisoners at Guantanamo Bay from analysis of multiple news sources.
The results: almost half the foreigners taken from Afghanistan were from the Arabian peninsula (160 from Saudi Arabia, 253, from the Arabian peninsula as a whole), less than 0.2% were from Iraq and there are more Brits than from any other European country.
Going to war with Iraq, meant that you removed a tyrant and had control over almost exactly the same oil reserves (Iraq plus Kuwait) as Saudi Arabia. This would mean that you could tighten the screws there, or be covered if there were a revolution, without drying up the pipeline of oil. Playing hardball with Saudi directly would not have been possible. Just a thought.
Saudi Arabia 160
Yemen 85
Pakistan 82
Afghanistan 80
Jordan 30
Egypt 30
Algeria 19
Morocco 18
Kuwait 12
China 12
Tajikistan 11
Turkey 11
Britain 9
Tunisa 8
Russia (not including Chechnya) 8
France 7
Bahrain 7
Kazakhstan 5
Australia 2
Canada 2
Chechnya 2
Uzbekistan 2
Syria 2
Georgia 2
Sudan 2
Bangladesh 1
Belgium 1
Denmark 1
Sweden 1
Germany 1
Iraq 1
Kenya 1
Libya 1
Mauritania 1
Qatar 1
Spain 1