Even amid the coronavirus pandemic that has wreaked havoc in both the United States and Iran, political and military escalation has continued between the two countries as they pursue conflicting interests in Iraq and the region. Friday marked 100 days since a heightened US-Iran confrontation led to Iranian forces shooting down a Ukrainian passenger jet leaving Tehran, killing all 176 people on board, but the tensions have not dissipated. The “Green Zone” in Baghdad where the US embassy is located was targeted sporadically with rockets fired by Iraqi militias in January and February. A major attack on March 11 killed three service members, two of them American and one British, at a joint base north of Baghdad. The US responded with air strikes, hitting five locations of the pro-Iran Kataib Hezbollah militia in Iraq on March 13. It also increased sanctions and designations on pro-Iran militias and Iranian officials. On April 1, US President Donald Trump warned Iran of “a heavy price” if its militias attacked American forces or installations. He even threatened the possibility of retaliation inside Iran. The next day the US deployed Patriot missiles in Iraq, against Iran’s wishes. The tensions stoked by the exchange of threats and bitter rivalry, especially over influence in Iraq, took another military turn this week. On Wednesday, the US Navy accused Iran's Islamic Revolutionary Guard Corps of harassing five American ships in the Gulf. The US Fifth Fleet tweeted that 11 Iranian vessels “repeatedly conducted dangerous and harassing approaches" towards five US Navy ships in the north Arabian Gulf. The escalation has raised questions in Washington about the status of US deterrence against Iran that the Trump administration claimed after the killing of IRGC general Qassem Suleimani in Baghdad on January 3. The “repeated dangerous and provocative behaviour by Iran’s navy against US ships on the Gulf is unacceptable”, Mr Trump’s former national security adviser John Bolton said on Twitter. The US has “been too lenient in responding to these incidents”, Mr Bolton, a hawk on Iran, said. “We must act to re-establish deterrence.” But the US strategy remains vague beyond imposing sanctions and maintaining a military presence in Iraq and the Gulf. Mr Trump is also under pressure to avoid military escalation from Congress, which passed legislation in March that would block a US president from taking unilateral military action against Iran. Mr Trump is expected to veto it. On March 27, Democratic leaders in Congress wrote a letter to Mr Trump urging discussions on any military action overseas. The US administration has been focusing its efforts on fighting the pandemic that has caused more than 34,000 deaths in the country, and Mr Trump is consumed by its impact on the US economy and his prospects for re-election. For the next six months, as the US effectively enters election season ahead of the vote on November 3, the scope of any US-Iran escalation will have an impact on the race between Mr Trump and his Democratic opponent Joe Biden.