Late this November, seven countries including Iran and the United States forged a historic deal to freeze major parts of Iran’s nuclear program in exchange for sanctions relief from the US and other countries. 
Less than a month into the deal, tensions have already resurfaced, with the US expanding the reach of its current sanctions despite protests from Russia and Iran.  While the deal with Iran is not perfect, this sanctions-heavy approach on the part of the US ignores decades of history and will inevitably fail to stop Iran if the country truly wants nuclear weapons.
Looking at past sanctions regimes hardly paints a rosy picture for sanctions against Iran. In recent history alone, one can look to the brutal legacy of sanctions against Iraq under Saddam Hussein. Lasting from 1990 through Hussein’s overthrow in 2003, the sanctions killed somewhere between 100,000 and 300,000 according to sources ranging from the Iraq Ministry of Health to Richard Garfield, a researcher at Columbia University.  At the same time, Hussein stayed in power; it took a military invasion to finally force the dictator out of power.
Similarly, the US’s 50-year-old embargo against Cuba seems to have borne little if any fruit over the past half-century. Despite the embargo, the Cuban economy has continued to grow at a steady clip,  and as Slate blogger Matthew Yglesias pithily remarked, “Embargo of Cuba Has Failed to End Communism.” 
These two examples demonstrate some of the problems with sanctions programs, but at least the US had tangible reasons to implement and maintain those sanctions in both cases. Iraq had an oppressive dictator who once used weapons of mass destruction. Cuba was the closest Communist regime to the US. Now, in the case of Iran, the US used sanctions to halt its burgeoning nuclear weapons program.
Iran has a nuclear program, and they could easily build a nuclear warhead if we would only reduce our sanctions. Once that happens, it will only be a matter of time before Iran uses their nuclear weapons against their sworn enemy: Israel. Iran’s warmongering would spell ruin for the entire Middle East, and sanctions are the only nonviolent way to save the region.
That is the narrative promoted by sanctions hawks. The only problem is that it’s false.
First, the notion that Iran is moments away from a nuclear weapon is less than credible. US and Israeli defense agencies alike have made numerous claims that Iran was on the cusp of weaponization. They feared nuclear weapons in 2000, 2003,  and 2007.  Those years came and went without nuclear weapons in Iran. Sanctions never materialized until 2006.
Of course, these fears of nuclear weapons assume that Iran is still pursuing a nuclear weapons program. US intelligence concluded back in 2007 that Iran already abandoned nuclear weapons production, and they believed that Iran made this decision as far back as 2003. 
This fact reveals two crucial insights. First, it means that the international community put sanctions in place to stop a nuclear program that had already stopped itself. Second, and perhaps more importantly, if Iran has a nuclear weapons program today, it only started that program after the start of sanctions.
With that in mind, there are only two conclusions that one can reach in this situation. Either the sanctions are unnecessary because the nuclear weapons program they seek to end no longer exists, or the sanctions have already failed to deter Iran from creating nuclear weapons.
In the second scenario, the sanctions failed for a simple reason. It’s a reason that makes intuitive sense, but that most people don’t think about. Iran is trying to defend itself. It is a majority Shiite country surrounded by Sunni countries and Israel, and its neighbors all have the funding and support of the United States of America.
Yes, Iran can find some diplomatic support from Russia, but that pales in comparison to its neighbors’ access to US military supplies and foreign aid funds. If they so decided, Iran’s neighbors could easily invade the country. The only way for Iran to defend itself is to acquire nuclear weapons.
This is only one possible scenario. Iran may have no reason to build nuclear weapons, and in that case, we return to the notion that international sanctions are unnecessary. If Iran is building nuclear weapons for self-defense, though, no amount of sanctions will stop that weapons program. Sanctions can only drive Iran further into desperation. They didn’t end dictatorship in Iraq, they haven’t ended Communism in Cuba, and they won’t end nuclear weapons in Iran.
Image courtesy of lobelog.com