How Might Iran’s “Axis of Resistance” Test Biden?

by Michael EisenstadtChristine McVann

Jan 16, 2021/ The Washington Institute


Michael Eisenstadt

Michael Eisenstadt is the Kahn Fellow and director of The Washington Institute’s Military and Security Studies Program.

Christine McVann

Christine McVann, a lieutenant colonel in the United States Air Force, is a 2020-21 military fellow at The Washington Institute.

Brief Analysis

The new administration could face an Iranian military strike as early as inauguration day, along with multiple threats from the Assad regime, Hezbollah, and other actors down the road, all requiring clear demonstrations of U.S. resolve.


Media  – If past is prologue, President Joe Biden’s incoming administration is likely to face early challenges in the Middle East, whether from adversaries deliberately attempting to gauge its resolve, a chance event that tests American leadership, or both. Even without intentional efforts to challenge the new president, the kaleidoscopic nature of the post-Arab Spring regional landscape ensures that incoming officials will have to deal with substantial tensions, discord, and complex diplomatic challenges involving both friends and adversaries.


In the waning days of the George H. W. Bush administration, Saddam Hussein launched a series of provocations that morphed into early tests for President Bill Clinton. The regime challenged U.S. no-fly zones over Iraq, attempted to obstruct UN weapons inspections, and sent troops across the border into Kuwait, leading to several military clashes. Later, an Iraqi plot to assassinate former president Bush during his April 1993 visit to Kuwait prompted a U.S. cruise missile strike that June.

In 2017, newly elected president Donald Trump faced early regional tests of his own, this time from Syria. In April, Assad regime forces used chemical weapons in a devastating attack on civilians at Khan Sheikhoun. In May-June, pro-Iran militias and armed drones repeatedly probed the small U.S.-British garrison near the border town of al-Tanf, while the regime launched an airstrike against the Syrian Democratic Forces (SDF) and their U.S. advisors near al-Tabqa. All of these challenges were met by force, which put America’s adversaries on their back heels and led them to cease such activities, at least temporarily.

Today, Iran, its proxies, and the Syrian regime—the so-called “axis of resistance”—will likely be among the first to test President Biden. How his administration responds to these initial challenges will in turn set the tone for future interactions with these actors and adversaries elsewhere in the world.

Potential Tests From Iran

The most daunting challenge could be an Iranian attack in the waning hours of the Trump administration on January 20, to avenge the killing of Gen. Qasem Soleimani one year earlier and reprise the inauguration day release of U.S. embassy hostages in 1981. Tehran may calculate that the Trump administration would not have time to launch a significant response before leaving office, while the Biden administration might not be inclined to do so immediately upon entering office. Iranian leaders may also assume that an attack would create leverage over the new administration.

Even if it eschews such an attack, Tehran will likely use various nonkinetic means to pressure the Biden administration into rejoining the Joint Comprehensive Plan of Action without making concessions of its own. Earlier this month, for example, it violated JCPOA caps by resuming its enrichment of uranium to 20 percent, then seized a South Korean-flagged tanker, which it apparently hopes to trade for $7 billion of Iranian funds held in escrow by Seoul.

In addition, the regime might attempt a number of other actions:

  • Barring access to nuclear inspectors from the International Atomic Energy Agency
  • Encouraging proxies to ramp up attacks on U.S. interests in Iraq using rockets and improvised explosive devices
  • Prodding Yemen’s Houthi rebels to intensify attacks on Saudi Arabia or launch strikes on Israel
  • Accelerating efforts to divert foreign oil tankers in the Persian Gulf
  • Resuming its harassment of U.S. naval vessels
  • Testing a ballistic missile to a range exceeding its current claimed cap of 2,000 kilometers, thereby signaling rejection of any limits on its missile program
  • Attempting a destructive cyberattack against the U.S. financial sector or critical infrastructure
  • Attacking Israeli territory or interests in retaliation for the country’s presumed role in two incidents last year: the sabotage of the Natanz centrifuge assembly plant and the killing of nuclear scientist Mohsen Fakhrizadeh. Iranian attacks of this sort could result in escalation that requires U.S. crisis diplomacy.


  • The Biden administration’s response to an inauguration day attack would be dictated by its scope, nature, and toll. Although a hasty response is undesirable—better to do it right than fast—failure to answer would likely beget further challenges, harden Tehran’s negotiating stance, and weaken domestic support for rejoining the JCPOA. In contrast, a firm response would bolster the new administration’s credibility, increase U.S. leverage in negotiations, and help deter Iran from attempting a nuclear breakout on President Biden’s watch if negotiations do not bear fruit.
  • Although restating its readiness for negotiations would enable the Biden administration to seize the high ground, officials should avoid conveying a sense of urgency to rejoin the JCPOA lest this harden Tehran’s bargaining position. After all, Iran has been cautious about advancing its nuclear program for more than three decades now, at least in part because it knows the U.S. military has the capabilities required to halt a nuclear breakout attempt. The Biden administration should ensure that these capabilities are ready and that relevant military plans have been updated.
  • The new administration should craft overt and gray-zone options for pushing back against Iran’s regional activities in a way that does not hinder diplomacy or engender a domestic backlash in the United States. It should also consult closely with Israel and key Arab partners regarding negotiations with Iran so they do not feel the need to influence diplomacy from “outside the room.”

Potential Tests From Syria

The Assad regime may see an opportunity to retake territory currently outside its control by renewing pressure on U.S. forces in al-Tanf, Deir al-Zour, and the northeast, perhaps in cooperation with Russia, Iran, and its proxies. Such action could include efforts to flip the Kurdish-led Democratic Union Party (PYD), which forms the backbone of the U.S.-supported SDF, or to lure away some of the SDF’s Arab tribal units. The return of regime forces might in turn give the Islamic State renewed opportunities to recruit new terrorists and regain strength in these areas. Regime forces might also use chemical weapons (CW) in one of the country’s remaining pockets of resistance, forcing the Biden administration to define its policy regarding CW use and violations of the Chemical Weapons Convention.


  • Maintain a small residual military presence in Syria (perhaps somewhat larger than at present), which would provide leverage over the Assad regime, Iran, and Russia at very low cost in blood and treasure while simultaneously protecting several million Syrians in areas beyond regime control.
  • Uphold the CW redline maintained by previous administrations as well as the fraying norm against CW use in general (e.g., Russia and North Korea have used CW in recent assassinations). At the same time, acknowledge that small arms, artillery, and barrel bombs have killed many more people in Syria than CW, making them the war’s true “weapons of mass destruction.” Simply upholding the CW redline will not be enough to prevent additional bloodletting in Syria.
  • Continue supporting the Israeli gray-zone campaign against Iran and its proxies in Syria. This campaign serves U.S. interests by preventing the Islamic Revolutionary Guard Corps (IRGC) from transforming Syria into a springboard for projecting power in the Levant, without producing escalation there.

Potential Tests From Hezbollah

In recent years, Hezbollah’s most important strategic project has been the Iranian-supported effort to produce upgraded rockets and missiles in Lebanon—a program that was started in part because weapons sent from Iran are often interdicted en route. Hezbollah intends to retrofit hundreds of heavy rockets with guidance packages and manufacture highly accurate missiles at underground workshops in densely populated areas of Beirut. If it obtains large numbers of these precision missiles, the group could saturate Israel’s defenses, target its critical infrastructure, and inflict serious long-term harm on its economy and morale. For this reason, the precision project is also critical for Iran, which considers Hezbollah’s rocket and missile force as part of its strategic deterrent.

Israel has declared that it will not allow Hezbollah to complete these workshops and has worked tirelessly toward that end, with much success so far. Its efforts include interdicting shipments of missiles, components, and production equipment in Syria. For its part, Iran has tried—without success—to thwart Israeli aerial interdiction operations by bolstering its air defenses in Syria. Once the Biden administration is in place, Tehran might intensify these efforts in order to provoke an escalatory response, in the hope that Washington will press Israel to halt airstrikes in Syria and related reconnaissance overflights of Lebanon. If interdiction efforts falter, Israel might accept greater risk in undertaking these airstrikes, which could increase the potential for escalation in Syria or—less likely—a war with Hezbollah in Lebanon.


  • Make clear that the United States will continue supporting Israel’s efforts to interdict arms transfers passing through Syria, thereby averting the need for future strikes against missile workshops in Lebanon that could spark a war. Washington should emphasize that this support will not be affected by efforts to renew nuclear diplomacy with Iran.
  • Include the precision missile project in any negotiations regarding Iran’s destabilizing regional activities.
  • Work with France and other allies to pressure Hezbollah. Washington should also publicly release information on how Hezbollah’s construction of missile facilities in heavily populated areas endangers Lebanese civilians, to generate pressure from the Lebanese public to shutter these facilities, and from Lebanese government officials who may fear the loss of U.S. military aid if these activities continue.


The Biden administration may be challenged on its very first day, so it will need to hit the ground running. First impressions are important, and the new president’s response to early tests will set the tone going forward for U.S. ties with allies and adversaries alike. A firm defense of American interests would bolster U.S. credibility, earn the administration good standing with partners, and, perhaps, buy time by deferring additional challenges. Yet failure to project resolve would likely embolden U.S. adversaries, with reverberations far beyond the Middle East.

Michael Eisenstadt is the Kahn Fellow and director of the Military and Security Studies Program at The Washington Institute. Christine McVann, a lieutenant colonel in the U.S. Air Force, is a 2020-21 military fellow at the Institute. The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Air Force, the Defense Department, or the U.S. government.

Michael Eisenstadt


Michael Eisenstadt is the Kahn Fellow and director of The Washington Institute’s Military and Security Studies Program.


Christine McVann


Christine McVann, a lieutenant colonel in the United States Air Force, is a 2020-21 military fellow at The Washington Institute.


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