Before 1 January 2021, will there be a lethal confrontation between the national military forces of Iran and the United States either in Iran or at sea?
Regional tensions in the Middle East are running high since attacks against commercial vessels in the Gulf of Oman, the downing of a U.S. drone, and missile attacks on Saudi oil fields in 2019 (BBC, NBC News, Al Jazeera). The deaths of General Qasem Soleimani and others in a 3 January 2020 U.S. missile strike in Baghdad in the wake of attacks on the U.S. embassy in Iraq have further inflamed tensions, with Iran warning of retaliation (BBC, NBC News). A lethal confrontation is one that results in at least one fatality (total, not each) for the national military forces of either side. For the purposes of this question, Iran's national military forces include the Revolutionary Guard Corps and Law Enforcement Forces. A lethal confrontation taking place in Iranian airspace or international airspace over the sea would count.
NOTE 15 January 2020: due to a forecaster inquiry, we have added the last sentence above regarding Iranian and international airspace. This does not change the question, but rather makes our handling of some particular scenarios more clear.