How did the shift between U.S. Presidents George W. Bush and Barack Obama both change and perpetuate American foreign policy toward terrorism and the wars in Iraq and Afghanistan?

What will be an ideal response?

Varies. After the transition, on the one hand, President Obama reversed many Bush administration policies. Obama upgraded diplomacy and downgraded the use of force, withdrew all American forces from Iraq, and emphasized multilateralism and international institution building. On the other hand, President Obama perpetuated other significant Bush administration policies. Obama continued policies of surveillance; escalated drone strikes in Afghanistan, Pakistan, Yemen, and elsewhere; reinserted American forces into Iraq to fight ISIS; and reconsidered the plan to withdraw all American forces from Afghanistan.