(CNN) COVID-19 presents a once-in-a-generation challenge. But this painfully unpredictable new world conjures a risk of miscalculation between global adversaries, in conflicts where knowns and norms held crisis at bay.

It throws normal assessments off balance. It introduces the possibility that a troublesome neighbor may be weak, or a long-term threat not as threatening as it has been for the past decades. Governments or militaries may see opportunity -- or danger -- where before certainties of response meant they ruled it out.

As I write, an extraordinary tit-for-tat is occurring between the Iranian-backed Iraqi Shia militia group Kataib Hezbollah and the United States. Three Coalition personnel were killed by rocket fire in Iraq , prompting CENTCOM to retaliate, leveling Kataib Hezbollah facilities and possibly killing their personnel.

In normal times, this would chime with the US killing in January of top Iranian commander Qasem Soleimani, and hint at an escalation towards open conflict. Does the minimal attention this escalation is getting mean it will pass without further incident, or rapidly develop into something worse? We simply don't know. Against the backdrop of a pandemic, all normal bets are off.

Iran is the first, big uncertainty in the equation. COVID-19 has likely left it vulnerable, weak and angry. Washington's campaign of "maximum pressure," sanctions and other less visible methods of punishment, has inflicted some damage. But according to Ali Vaez, Crisis Group's Iran Project Director, the Trump administration may see "the outbreak as the final nail in the Iranian economy's coffin and (be) likely less interested in any mutually beneficial compromise."

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