As concerns grow over Russian President Vladimir Putin’s nuclear saber-rattling, what would a U.S. response look like?

While U.S. officials have stressed there are plans being developed to counter a range of moves by Moscow, they have thus far kept specifics under wraps.

Here are some of the options reportedly under consideration:

1. Economic sanctions: This is seen as the least provocative option, and one that would likely have the most international support. It would also be the easiest to implement, as the Treasury Department has already put together a list of high-profile Russian individuals and entities that could be targeted.

2. Military action: While not off the table, this is considered a last resort due to the risks involved. Possible scenarios include positioning additional U.S. troops and equipment in NATO countries bordering Russia, or carrying out precision strikes on Russian targets in Ukraine.

3. Cyberattacks: Stuxnet-style malware could be used to take down critical infrastructure inside Russia, or disruptive attacks could be launched against government websites and other online resources.

4. Forcefully breaking up Russia’s energy exports: This would involve using diplomatic and economic pressure to dissuade European countries from buying oil and gas from Russia, which is its main source of revenue.

5. Supporting regime change in Moscow: While this option is not being actively pursued by the Biden administration, some hawkish lawmakers have called for it. This would likely involve funding opposition groups inside Russia and working to foment popular discontent with Putin’s rule.

With tensions between the U.S. and Russia at their highest levels since the end of the Cold War, it’s clear that somethingneeds to be done to prevent further escalation.

The question is, what? economic sanctions, military action, cyberattacks, breaking up Russia’s energy exports, or regime change in Moscow?