The most important single thing the west can do...

President Bush said,

"Let's join hands as wealthy industrialised nations, and say to the world, we're going to get rid of all our agricultural subsidies together. And so the position of the US Government is we're willing to do so, and we will do so with the, uh, with our fine friends in the European Union."

Let's fantasise that it happens. What results?

Food in the west gets cheaper immediately.

Farmers in the west become competetive, since there is now competition.

Western farmers stop being dependent on handouts.

Western consumers pay less for food at the shop, and pay less in taxes for welfare (since food is cheaper), and pay less in taxes again since the subsidies aren't being paid.

Unproductive farmers go into other lines of work, no longer wasting their abilities on subsidy chasing.

What about the third world? Their agricultural products are suddenly marketable.

They have an incentive to grow for more than just subsistence.

Western imports of food increase, making western consumers more dependent on third world suppliers.

Conditions in third world hellholes become important to the western economy. Tyrants in those hellholes are bad for business, so important voices in the west pressure Western goverments soactually do useful things to depose them.
At a stroke, this could be the greatest positive change that western governments could possibly do on their own to improve the material lot of the planet.

Neeeeever happen.