Iran has spent many years exploiting the weakness of Bashar al-Assad’s regime to entrench its forces in Syria, hoping to emerge out of that country’s eight-year-long civil war in a much stronger position. This is part of Iran’s grand strategy in the Middle East, which also seeks to take over parts of Iraq’s government and to leverage its influence over Lebanon’s political system. Little stands in Iran’s way, since the US has indicated its long-term objective is to quit Syria entirely while its role in Iraq is limited to fighting ISIS. Iran’s role in Syria increasingly threatens Israel, as revealed through recent tensions and numerous air strikes on Iranian targets that Israel has said it carried out over the years.Iran’s role in Iraq has been spotlighted by the 700 pages of documents leaked from Iran’s intelligence services to The Intercept and The New York Times. In Syria, Iran’s role is murkier but also well known. Iran has so many forces in Syria that in 2018 the US included in its official policy the “removal of all Iranian-led forces and proxies from the country.” A recent study by the US Defense Intelligence Agency included classified information on Iran’s presence, but a recent Inspector General report about the US-led operations against ISIS noted that “the bulk of Iranian-commander forces were concentrated in the western half of Syria prior to the USS withdrawal.” Iranian-backed militias are in close proximity to US forces “as part of the Iranian goal of forging ground lines of communications from the Iraqi border.”Satellite images from ImageSat International show Iran is continuing to construct its Imam Ali base near Albukamal on the Iraqi border. Other reports indicate that Iran had up to 19 bases in Syria in 2018.From Iran’s perspective, Syria has been a key ally and a conduit for arms shipments to Hezbollah. This has gone back decades. But Iran knew in the early 2000s that the Assad regime was flirting with the West in the hope of balancing Tehran’s role. The eruption of the Civil War in 2011 led the Assad regime deeper into the hands of Iran, making it more dependent on Tehran and Moscow. Increasingly the regime was hollowed out, losing tens of thousands of casualties that it couldn’t replace, and inviting in more of the IRGC and IRGC allies such as Hezbollah and Shi’ites recruited from Afghanistan, Pakistan and Iraq. Syria became a modern version of what Germany looked like during the Thirty Years War, a black hole of suffering upon which was built a chessboard for foreign powers.The Syrian civil war began as one between Syrians. It looked like Syria had fallen into chaos, like Libya in 2011. In fact, the regime’s crackdown and the use of foreign troops led to years of destruction as step by step non-Syrian actors moved in. Hezbollah in 2012-2013, ISIS and 50,000 of its foreign fighters in 2014, Russia in 2015, Turkey in 2016, and of course the US and Iran. The US, backing the Syrian Democratic Forces, came to control a third of Syria. Turkey seized another 20%. The regime eventually defeated the rebels in the south in the summer of 2018. But the regime then watched as Russia gave its approval for the Turkish operation against Kurdish fighters in Afrin in January 2018, and also signed an Idlib ceasefire in September 2018. Russia was now the guarantor of Turkey’s role, because Russia was selling Turkey the S-400 air defense system. Russia, the ally of the Syrian regime, was also a kind of enabler of Turkey’s role. Russia could turn over more areas or not. It signed another deal on October 22 enabling Turkey to grab areas it had taken from the SDF and the Americans in October.Now Syria appears partitioned between Turkey in the north, a fading US influence in the east and south, and a growing Iranian influence in the south. Russia plays the grand master watching all of this unfold. But Russia is not seeking to confront the US, Iran or Turkey. Russia’s goal is to use Sochi and Astana, and even Geneva, to bring Iran and Turkey to the table again and again. The US is cut out from this process. Regardless, the US sought to exclude its own SDF partners from Geneva. Thus in the long term, the US role in Syria is likely going to be deeply reduced or eliminated entirely.But Iran’s role will likely grow. The problem for Iran is that it has too many objectives in Syria. It wants to cement its bases. It wants to build its “land bridge” to the Mediterranean Sea and Hezbollah, with an off-ramp toward the Golan Heights. It wants to sign deals with Assad. And it wants to project influence along the Euphrates River valley towards Deir Ezzor.All the while, Iran is struggling economically. Protests at home are harming its abilities abroad. It has an uphill struggle in Syria to maintain and expand its role. Iran has the technology that it wants to transfer, the precision guidance for missiles for instance, that it hopes to put in Hezbollah’s hands. But it must be careful because protests in Iraq have also targeted Iran’s presence. Protests in Lebanon have also led to uncertainty there. Iran faces now what all great powers face as they become too powerful. They must manage their power. Iran says it is the “resistance.” But people are now “resisting” Iran throughout the region and at home. Its bases are clear targets, and it has difficulty conducting truly clandestine affairs. Its main power is in human resources and deepening its human ties to places in Syria, Iraq and Lebanon. This is how it gets its power, through its network of Shi’ite allies, and places like the Sayyida Zaynab shrine in Damascus where pro-Iranian fighters gather.Now Iran must decide its next step in Syria. The role of its IRGC Quds Force has been key to supporting the Assad regime while also benefiting on the side. But Iran understands that its role is entangled with the regime and also with Russia. Its presence must not undermine either of these two. In addition, the Syrian regime and Russians are focused more on the north today, while there are questions about what the US is doing in the east. In the south and west, therefore, Iran’s forces have been targeted by Israel in recent years. Iran’s IRGC boasts that it believes the destruction of Israel is no longer just a dream. Towards that end, it has invested in new missiles, drones and other technology which it has transferred to Iraq, Syria and Lebanon.While those transfers have made Iran’s role in Syria even more dangerous, any seasoned chess player knows that pieces spread too thinly across the chessboard may result in checkmate.