In its unannounced war against Ukraine, Russia relies on covert operations which fall squarely within the definition of "international terrorism" under 18 U.S.C. § 2331.
Specifically, armed operatives of Russia, acting under disguise, attempt to influence the policy of Ukrainian government by intimidation or coercion.
They also try to affect the conduct of a government by assassinations and kidnapping, taking by force government buildings, police posts and military bases of Ukraine.
This activity is being conducted on large scale and over prolonged time period, despite condemnation by the USA, G-7, NATO, EU and UN.
Accordingly, Russia must be officially designated as "State sponsor of terrorism", per http://www.state.gov/j/ct/list/c14151.htm