Article 1 of the treaty, which the US has ratified in full, details a definition of torture. The protocol to the treaty dosn't cover definitions as far as I can see, it only covers the makeup of torture prevention comittees.

it's not technically illegal under US law for the Bush regime to redefine what's torture to exclude torture by waterboarding.

You'd have to say that it is the most transparent sophistry. However there is case law that has come to light. Sleep deprivation, waterboarding etc have been convicted as war crimes after World War 2

AmericanHeritage.com / Blog: Waterboarding

In 1947 the United States convicted and imprisoned a Japanese officer, Yukio Asano, for abuses of an American civilian that included a version of waterboarding, and included charges of what would now be called waterboarding in other cases against Japanese accused of torture. The United Kingdom executed Japanese who carried out versions of waterboarding during World War II, and Norway tried Germans for similar activities.

I am also not a lawyer, but I do know bullshit when I see it.

Any idiot can face a crisis - it's day to day living that wears you out.