What is the Obama doctrine with respect to Islamo Fascism as compared to the policy of George Bush?
'Islamofascism' is a neoconservative term that has no functional meaning or relevance in the real political world, so no one except a neoconservative would bother establishing a policy with respect to it.
What is the Obama Doctrine, in terms of foreign policy?
Screw your friends and let your enemies screw you
What is the doctrine of implied powers?
Implied powers are those used by Congress to implement laws, policies, sanctions, etc. that are not explicitly defined in the Constitution yet deemed necessary and proper. A perfect example would be the existence of the Federal Reserve Bank. Though the Constitution doesn't grant the power to make a bank, it was done. Others include Income Tax and the Military Draft.