The American decision to invade Afghanistan remains mired in controversy, despite the fact that it occurred more than eight years ago. During the presidency of George W. Bush, the United States faced the worst terrorist attack ever carried out on US soil. The hijackings on September 11th, 2001 effectively changed the world and the decision of the United States to invade Afghanistan less than one month after the attacks of September 11th was a watershed moment in world history. The ramifications of this decision continue to resonate, as NATO forces remain committed to eradicating the Taliban presence from the rural regions of Afghanistan and the United States remains and embroiled in quelling the insurgency. The United States’ decision to invade Afghanistan took place almost immediately following the attacks of 9/11 and led to the successful overthrow of the Taliban, an extremist and violent Islamist organization which had run Afghanistan through fear and brutality. That Afghanistan is one of the poorest countries in the world and remains severely underdeveloped has been a feature of this country’s existence for centuries. The American decision to invade Afghanistan remains controversial for some but has been justified as being legal and within international law. To what extent was the war in Afghanistan, against both the Taliban and Al Qaeda, justified according to article 51 of the UN Charter? To what extent was the behavior of the United States justified in line with the principle of self-defense? While the invasion was successful and led to the overthrow of the Taliban in 2001, the insurgency continues and the consequences of such an event continue to resonate on the lives of average Afghans. Afghanistan remains in the news, as the shady reelection of Hamid Karzai reflects, and the international community has a vested interest in ensuring the peace and stability of this war-torn country.