The wars in Afghanistan and Iraq should be considered separately when discussing their respective origins and histories. While President George W. Bush’s decision to invade Iraq in 2003 was highly controversial and ultimately, according to many, unnecessary, the invasion of Afghanistan was considered entirely legitimate, although one might question the manner in which the war in Afghanistan was subsequently conducted.

The terrorist attacks on New York City and Washington, DC, represented the most traumatic and deadly attacks on American soil since the Japanese surprise attacks on US military installations in Hawaii in 1941. Al Qaeda, the Islamic terrorist organization that organized and carried out the attacks of September 11, 2001, had declared war on the United States and had carried out a previous series of terrorist attacks, including on two US embassies in East Africa, and constituted an ongoing threat to the United States. The decision to invade Afghanistan was widely acknowledge as legitimate. That the conduct of military operations in Afghanistan, where Al Qaeda was sheltered by that country’s brutal and extreme Taliban movement, was adversely influenced by developments in Iraq does not detract from the legitimacy of the initial decision to invade.

When discussing the situations in Afghanistan and Iraq and popular perceptions at the time, it is useful to go back and consider a speech before a gathering of military veterans made by President Barak Obama in August 2009. In that speech, the president stated, regarding his decision to expand the American role in Afghanistan,

We must never forget, this is not a war of choice. This is a war of necessity. Those who attacked America on 9/11 are plotting to do so again. If left unchecked, the Taliban insurgency will mean an even larger safe haven from which Al Qaeda would plot to kill more Americans. So, this is not only a war worth fighting. This is fundamental to the defense of our people.

Regarding the idea that the decision to invade Afghanistan was justified by circumstances, its prosecution was adversely affected by what President Obama and many others viewed as the “war of choice.” President Bush was determined to invade Iraq, and the preparations for doing so involved the diversion of important military units from Afghanistan to Iraq, thus leaving the former unfinished. The war in Afghanistan subsequently become a quagmire from which presidents have proven unable to extricate the United States.

The justifications for the invasion of Iraq included, first and foremost, the mistaken belief that Iraqi President Saddam Hussein, an extraordinarily brutal dictator, had continued his quest for nuclear, chemical, and biological weapons. Following the first Persian Gulf War in 1991, it was believed that the Iraqi regime continued to conceal weapons programs that were banned by the United Nations. International sanctions that had kept Iraq’s economy and military in a weakened state were beginning to fragment, as countries like Russia, France, and Germany were eager to both buy Iraqi oil and sell to Iraq weapons and infrastructure-related material.

The belief, repeatedly buttressed by the US Intelligence Community, that the programs for weapons of mass destruction continued to exist, alongside increasing international pressures to lift the sanctions, provided all the incentive President Bush needed to invade. The weapons the US feared were proven to no longer exist (President Hussein had wanted his arch-enemy Iran to believe Iraq was still armed with such weaponry), and the invasion turned into yet another quagmire.

The invasion of Iraq is considered a mistake because the main justification for the invasion, the nuclear, chemical, and biological weapons that no longer existed, was proved wrong. The invasion of Afghanistan was not considered a mistake; on the contrary, it was almost universally applauded for removing the Taliban from power and weakening (but not finishing) Al Qaeda. The mistake was in believing that the United States could succeed where the British and Russians had failed and in prematurely turning our attention from Afghanistan to Iraq.