A primary tenet of conservatism is that government action or inaction affects human behavior. If taxes are raised, the economy worsens. If taxes are lowered, the economy improves. If guns are prohibited, crime rates rise. If gun ownership is legal, crime lessens.

In recent years, conservatives have reacted in outrage to what they consider to be intrusive airport security. Similarly, in my capacity as a talk radio host, I’ve done three-hour-long programs in which conservatives vent their frustrations with everything from the Department of Motor Vehicles to the local school board. When government acts, people react.

When nearly 3,000 innocent civilians were murdered by terrorist thugs on Sept. 11, 2001, many Americans were asking, “Why?” I did not ask this question. I was shocked. I was angry. But I did not wonder why we were attacked.

Neither did columnist Pat Buchanan. In his 1999 book A Republic, Not an Empire, Buchanan warned that a future terrorist attack against the United States was not only likely but described how it might play out: “It is in February of 2005 that the explosion occurs in the port of Seattle. It is a low-yield crude atomic device, but the devastation is incredible. Thousands are dead; thousands more are injured or wounded, many burned horribly … No one knows for certain who put the device there … But intense speculation focuses on a group associated with the financier of terror Osama Bin Laden.”

Like Buchanan, I was one of a handful of conservatives throughout the 1990s who believed the United States’ constant bombings, sanctions, and heightened American troop presence in the Middle East would give radical Islamists in that region unprecedented common cause against us. Two decades prior, Iran’s Ayatollah Khomeini had tried to declare jihad against the United States by pointing out that American culture was decadent. It allows pop music, alcohol, and pornography — our “freedoms.” This approach didn’t work.

To be sure, many religious Muslims despised our culture and considered America to be the Great Satan, but this was still not enough for them to plan a 9/11-style attack on the United States. So what changed?

Bin Laden himself mentioned the permanent presence of American troops on the Arabian Peninsula after the Persian Gulf War. He mentioned America’s relationship with Israel. The 9/11 mastermind cited U.S. sanctions on Iraq throughout the 1990s, which resulted in the deaths of 500,000 Iraqi children, the United Nation’s official number.

When Buchanan or anyone else, myself included, has tried to bring up these explanations for 9/11, our critics say that we are “blaming” America for the terrorist attacks. But searching for a motive is not an effort to blame anyone.

Terrorism is a tool of the weak, and the United States possesses the most powerful military in the world, so exactly how would we expect those who want to fight us to do so? Many Americans, with good reason, consider the nearly 3,000 deaths on 9/11 enough justification for almost any military action around the globe. Is it possible that 167 times that many deaths — in Iraq alone and children at that — would give Islamic terrorists all the justification they needed to plot against the U.S.?

The CIA developed the term “blowback” to describe the unintended consequences that often arise from military intervention, and it’s safe to say 9/11 was the largest case of blowback in American history. No doubt, radical Islam and the culture and economic conditions of the Middle East played a role, but that does not negate the primary cause of 9/11, our nation’s foreign intervention.

To say, as some conservatives do, that Islamists just decided one day to spread Sharia law globally because the Quran commands it is to also say that there must be something new and different about Islam. Has the Quran changed much since the days of our parents and grandparents who didn’t have to worry about Islamic terrorism? Or has something else changed?

And is it still changing? University of Chicago political scientist Robert Pape notes: “From 1980 to 2003, there were 343 suicide attacks around the world, and at most 10 percent were anti-American inspired. Since 2004, there have been more than 2,000, over 91 percent against U.S. and allied forces in Afghanistan, Iraq, and other countries.”

Is there any correlation between America’s vastly increased presence in the Middle East post-9/11 and the rise in suicide attacks? Is there a correlation concerning any future terrorist attacks on the American mainland? Does government intervention actually affect people’s behavior?

When it comes to American foreign policy, as long as it remains controversial to ask these common-sense questions a decade after the Sept. 11, 2001 attacks, our nation will have to worry about another 9/11.

Jack Hunter is the official campaign blogger for GOP presidential candidate Ron Paul, and he co-wrote Rand Paul’s The Tea Party Goes to Washington.