In its coverage of the Syrian civil war, the media has ignored a key factor that fuels the ongoing tragedy. We know a lot about the war crimes committed by the Syrian regime of Bashar Assad, and we also know that Iran and Russia are the key enablers of the Assad regime. However, few analysts have bothered to ask: who has been enabling the enablers? The answer contains the dirty secret of Syria.In her speech to the UN Security Council following the latest chemical weapons attack by the Syrian regime, US Ambassador to the UN Nikki Haley said, “We must not overlook Russia and Iran’s roles in enabling the Assad regime’s murderous destruction...after all, no civilized government would have anything to do with Assad’s murderous regime.”Unfortunately, the world has failed to hold Iran accountable for its pivotal role in the Syrian tragedy even though the facts are well known.Whereas Russia only entered the conflict in the past two years, since the outbreak of the Syrian civil war, Iran has gone out of its way to prop up the brutal regime of Assad.Experts estimate that since 2011, Iran has been spending between $6 billion and $35b. per year in Syria.Beyond its financial support, Iran has provided the Assad regime with an endless supply of ammunition and weapons and tens of thousands of fighters from its Revolutionary Guard Corps and from its loyal proxy, Hezbollah. In addition, Iran has recruited, trained and deployed thousands of loyal Shi’ite fighters from Iraq, Afghanistan, and elsewhere to Syria. It is important to know that the arm of the Iranian government that supports the Syrian regime and deploys foreign fighters to Syria is the Islamic Revolutionary Guard Corps, the IRGC. Specifically, it is the notorious Maj.-Gen. Qassem Suleimani, commander of the IRGC Quds Force, who runs the war in Syria.Absent the support of the IRGC, Assad would have fallen from power years ago and there could have been a peaceful resolution to the civil war.Hundreds of thousands of lives could have been saved and there would not be seven million Syrian refugees wandering the face of the earth.And why has Iran been investing so much blood and treasure in Syria? In an excellent article that addresses this question, Iran expert Karim Sadjapour quotes Ali Akbar Velayati, a senior adviser to Supreme Leader Khamenei. Velyati writes, “The chain of resistance against Israel by Iran, Syria, Hezbollah, the new Iraqi government and Hamas passes through the Syrian highway. ...Syria is the golden ring of the chain of resistance against Israel.”This explains why Iran is working to build a permanent military infrastructure in Syria.So here is the dirty secret of the Syrian tragedy: At the recent Munich Security Conference, former US national security advisor Lt.-General H. R. McMaster warned, “When you invest in Iran, you’re investing in the IRGC. You might as well cut the Islamic Revolutionary Guard Corps a check and say, ‘please use this to commit more murder across the Middle East.”McMaster makes a point that has been missing from the discussion of Iran and Syria. The IRGC is not just a paramilitary organization. It is also a major economic force in Iran.According to the website of United Against Nuclear Iran (UANI), “The IRGC now largely controls the petrochemical, banking, construction and telecommunications sectors in Iran. Estimates of IRGC control of the economy “range from a third to nearly two-thirds of Iran’s GDP – amounting to tens of billions of dollars.” Who is doing business in Iran today? Whereas US law prevents most American companies from doing business in Iran because it is designated as a “State Sponsor of Terror,” that is not the case for Asian and European companies. Since the lifting of economic sanctions under the Iran nuclear deal (the JCPOA), hundreds of major multinational companies have returned to do business in Iran – and investors should beware.If you are investing in Asian or European companies, then you should ask whether these companies are doing business in Iran. If they are, then there’s a very good chance they are doing business with the IRGC. And let there be no doubt, the business deals of Asian and European companies not only enrich the IRGC, they also send Iranian leaders the message that there are no economic consequences for their support for the war crimes of the Assad regime.There is a moral dimension to this reality that we cannot ignore.Each of us as investors has the power to choose where to put our money. And major institutions – including endowment funds and pension funds – have tremendous economic power. If we are to put an end to the slaughter in Syria, then we must demand that the international business community cut its ties with companies owned by the IRGC.The leaders of major Asian and European companies who do business in Iran have chosen to ignore the moral consequences of their decisions. They have chosen to be indifferent to the complicity of Iran in the murder and suffering of the people of Syria, simply for the sake of economic gain.The late Nobel laureate Elie Wiesel wrote in his famous book, Night, “On planet Auschwitz, human moral responsibilities are silenced and deformed into indifference.”We as investors must not remain indifferent to human suffering.We must not inadvertently help to enable the IRGC and its support for the war crimes of the Syrian regime.The author is outreach coordinator for the non-partisan advocacy group, United Against Nuclear Iran (UANI).