"This is an escalation," said Tatiana Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center toldThe New York Times. "I really believe the situation is very dangerous."
Moscow's missile was fired using a conventional warhead but "it could be refitted to certainly carry ... different types of conventional or nuclear warheads," Pentagon spokesperson Sabrina Singh said. Singh also described it as an "intermediate range ballistic missile."
Initial reports from Ukrainian officials said that the strike was an intercontinental ballistic missile, in contrast to Putin's characterization of the missile. According to the Financial Times, officials from Ukraine, Russia, NATO, and the U.S. have offered different exact classifications for the weapon.
Putin, in a televised address, made clear that the move was in response to Ukraine's use of western-made weapons to strike deeper into Russia.
The Ukrainian government had long sought the permission of western governments to use weapons like American-made Army Tactical Missile Systems, or ATACMS, and U.K.-produced Storm Shadow missiles. The U.S. began supplying the Lockheed Martin-produced ATACMS earlier this year, according to Defense One, but imposed restrictions on their use due to the escalatory implications of Ukraine using them to strike targets far inside Russian territory.
Ukraine launched strikes using both of those weapons this week following a policy shift from the Biden administration allowing their use, which at least one foreign policy expert cautioned was a "needlessly escalatory step."
"From that moment, as we have repeatedly underscored, a regional conflict in Ukraine previously provoked by the West has acquired elements of a global character," Putin said in his address, according to Reuters.
The comments come days after Putin also codified a change to the country's nuclear doctrine that lowered the threshold for potential nuclear weapons use.
Meanwhile, on the Ukrainian side, the country's former military commander Valery Zaluzhny offered a bleak prognosis of the war earlier this week, saying that he "believe[s] that in 2024 we can absolutely believe that the Third World War has begun."
The comments were in reference to the fact that Russia is enlisting the help of outside allies, such as North Korea, in its military effort.
Elsewhere, foreign policy experts cautioned against escalatory spiral.
Anatol Lieven, the director of the Eurasia Program at the Quincy Institute for Responsible Statecraft, offered an argument against what he sees as the underlying rationale of allowing Ukraine to attack Russia with U.S. and U.K.-supplied long range missiles.
"The official argument for the ATACMS and Storms Shadows decision is to put Ukraine in a stronger position before peace talks are initiated by Trump," he wrote in a piece published Thursday. "This is a dangerous gamble, because the missiles (which are guided to their targets by U.S. personnel) risk infuriating Russia without giving really critical help to Ukraine."
U.S. intelligence analysts have also warned that granting Ukraine the ability to use U.S., French and U.K.-supplied long-range missiles could prompt forceful retaliation by Russia; additionally, analysts cautioned that the missiles would likely not fundamentally change the course of the war.
In a similar vein to Lieven, Matt Duss, the executive vice president of the Center for International Policy and Robert Farley, an assistant professor at the University of Kentucky, argued in the pages of Foreign Policy this week that U.S. policymakers should pursue a negotiated peace for Ukraine, in part because "Ukraine does not have a path to a straightforward victory."
"If Trump makes good on his promise to end the war, supporters of Ukraine must be clear about the principles at stake and be careful not to let maximalist aims foreclose a durable negotiated settlement. We say this with the knowledge of what conceding Ukrainian territory to permanent Russian control could mean, and has already meant, for Ukrainians in those territories," they wrote.
