The Covid-19 pandemic neither fostered cooperation nor eased US-Iran tensions that reached their peak in the wake of the US killing of Iranian General Qasem Soleimani in January. Instead, the virus has been weaponized by Washington and Tehran under the assumption that it could provide new opportunities to force the other party to review its policies.

Since January, both countries are in the stage of immediate deterrence; that means they are engaged in short-term urgent attempts to prevent a specific, imminent attack that could emerge during a political crisis. However, Covid-19 is spoiling military threat assessments involved in such deterrence calculus. The pandemic's implications on military readiness and force projection have impacted the perceptions about the prospect of retaliation. Thereby, it has increased the risk that actors resort to opportunistic offensive policies to gain strategic leverage amid current political deadlock.

Some of the pandemic's implications on the military, such as defense supply chain disruptions, interruption in maintenance of weapon systems, and constrained defense spending, have longer-term effects rather than real-time operational consequences. However, concerns over probable deterrence deficit in a time of Covid-19 stem from the fact that the pandemic has the potential to degrade military capabilities in maintaining mission assurance and readiness while responding to a larger civilian request for support. In this way, the pandemic finds an operational significance.

On the US side, disruption in training pipelines was among the earliest effects of the pandemic. For example, the US Air Force is operating training with only fifty percent of its pre-pandemic capacity. The declining training hours, coupled with longer working hours due to protective measures, have raised the risk of errors in working with complex weapon systems. On the top, the pandemic has challenged critical aspects of US forward power projection and its ability to engage in sustainable large-scale contingencies. Playing a civilian role at home has breached the pre-pandemic US military resource allocation to global fronts designed to maintain deterrence with adversaries.

Essential functions for a hypothetical US war with Iran, such as agile logistics, medical resources, coalition-making, and interoperability have all been hindered by Covid-19. Agile logistics, which are the backbone of US operations overseas, are now widely involved in civilian support to the pandemic, casting doubts on the US’ actual ability to run a simultaneous wartime support 7,000 miles away in the Persian Gulf. Also, the Department of Defense’s movement restrictions, including the one issued by the CENTCOM, might end in lesser US logistical agility.

As of April 27, almost 61,000 military staff members, including 4,400 doctors, were involved in Covid-related operations, exacerbating an already existent doctor shortage in the US military. Also, the scale-down trend in allied operations is adding to constraints caused by stressed logistical and medical resources. At a time when military allies like Britain and France are weakened by internal security crises, the US has fewer possibilities of forming an effective military coalition against Iran.

On the Iranian side, Ayatollah Ali Khamenei on March 12 ordered setting up a Health and Medical Treatment Headquarters under General Staff Command. The new structure coordinates military assistance with civilian officials, raising the scope of the military's involvement in the pandemic. The broad military involvement is stressing Iran's military in general. Nevertheless, two factors are leading to the belief that it has not significantly impaired the country's deterrence posture.

First, the armed forces’ engagement in the fight against Covid-19 has remained limited in scope. The army and land forces of the Islamic Revolutionary Guard Corps (IRGC), as well as the Basij militia, which are the less critical elements of immediate deterrence, have been involved. In total, 80,000 army personnel, 700,000 Basij forces, and 35 percent of military hospital beds have been mobilized. In this way, the core of Iran's immediate deterrence structure, i.e. the missile and naval forces, has mostly remained intact. At the same time, Tehran has continued its conscription recruitments as business as usual, though introducing health measures to reduce the risk of an outbreak.

Second, the missile and naval forces forming the backbone of Iran's asymmetrical model of warfare rely on small operational units, facing fewer risks of decommissioning due to the outbreak. For example, Iranian Anti Access/Area Denial (A2/AD) assets in the Strait of Hormuz are operating with a handful of troops and have almost remained immune to the pandemic. On the contrary, in the US case, power projection assets such as naval units hosting thousands of personnel are more at risk of outbreak and possible decommissioning, such as seen in the case of the USS Theodore Roosevelt.

Yet, so far, the pandemic has not caused a significant erosion in the actual capabilities of both countries. However, it is impacting on threat assessments and perceptions of deterrence. In the US, there is a brewing perception that adversaries could take advantage of the chaos to prod American weakness as the US stumbles during the Covid-19 pandemic. Even one recently unclassified DoD report in 2017 cautioned about such scenarios. Secretary of Defense Mark Spencer, in a tweet, warned that adversaries who think now is the time to challenge the US are dangerously thinking wrong.

Iran, coping with complex interlinked socio-economic challenges, fears that Covid-19 costs and constraints could change US calculation in favor of a possible agression. In the eyes of Tehran, the hawks' assessment in Washington arguing that Covid-19 has significantly degraded Iranian warfighting power is worrying as it might eventually make its way into an official calculus. Reports on similar previous influences of lobbyist groups in shaping the Trump administration's policies are not few. It would ramp up miscalculation that could push US President Donald Trump into a collision course with Tehran. The IRGC, in an official announcement after the April tensions in the Persian Gulf, warned against such miscalculations.

Heighthened threat perception would likely push both countries to show off strength and expand offensive signaling in order to shape credible threats and restore immediate deterrence. Targeted training and exercises in the operational domains with direct contact are among the options to shape perceptions and influence the behavior of the other side. In March, the US Navy conducted an offensive exercise involving the expeditionary mobile base USS Lewis B. Puller to simulate both neutralizing the IRGC Navy (IRGCN) boats using army attack helicopters and practicing amphibious landing on Iranian coasts. The exercise, which was extended into April, sent a signal to Iranians about the combat readiness of US forces in the Persian Gulf.

The IRGCN responded with its signaling in kind. While the US Navy was conducting the exercise, eleven IRGCN vessels hampered the formation of Puller and six other vessels, forcing them to change their formation. Indeed, the IRGCN deterrence by denial maneuver aimed to check the US Navy’s forward power projection practice. Then, the military signaling was supplemented on the political front when President Trump threatened to destroy Iranian gunboats, and President Hassan Rouhani warned that Tehran is closely following US activities. The deterrence rationale likely motivated the IRGC's decision about the timing of its satellite launch amid the pandemic. It signaled that the IRGC's missile forces are in fully functional status.

Washington and Tehran are now engaged in a tenuous act of balancing between mitigating the Covid-19 outbreak at home and adopting policies to restore immediate deterrence. The risk rests on information uncertainty and the subjective perception of the level of military readiness in a time of Covid-19. The pandemic-constructed ambiguity is adding to fear of aggressive opportunism in US-Iran relations. When accompanied by the lack of a direct line of communication to remedy the foggy assumptions, it is only expected to ratchet up the risk of collision.