Opinion: The US can legally intervene in Ukraine if Russia decides to invade
Recent signs show that Russian President Vladimir Putin is seriously considering invading Ukraine. To help prevent that from happening, the United States has two options: the soft option and the hard option.
The soft option involves diplomatic measures such as increased sanctions and trade punishments like cutting off financial markets. Generally speaking, countries prefer utilizing this option to foster de-escalation for the simple reason that it is cheaper and minimizes civilian death and suffering. But there is a chronological component here: There must be enough time for the measures to work, and if there is not, countries’ hands may be forced to pursue the hard option.