Consider a few basic statistics and economics here.

The 'donation' proposed by Kuwait amounts to 1% of their GDP, or a staggering $250 per head of population.
The net US cost of $7bn in freeing Kuwait from Iraq amounts to 0.1% of US GDP, or $20 per head of population.

Why did the US have such an interest in Kuwait? Maybe because it buys 2,400,000,000,000,000,000,000,000 litres of crude PER DAY from the gulf. Cost to the US taxpayer of a permanent $1 rise in the cost of a barrel of crude is $10bn per annum.

Before you comment that 'its okay for me to say this from the UK' I will remind you our net cost of the first gulf war was approx 2.5 times the US per head. The UK got involved as we have a huge number of expats living in Kuwait, not because of the oil. We are net exporters of 50% of our own oil and price rises actually suit us