The proposition that Putin won’t be provoked by a U.S. decision to send lethal arms to Ukraine amounts to a hunch. It’s not supported by evidence, and Putin’s past behavior contradicts it. This is not a minor point: if he does ramp up the war and the Ukrainian army is forced into retreat, the United States will face three bad choices.
First, Washington could pour even more arms into Ukraine in hopes of concentrating Putin’s mind; but he can easily provide additional firepower to the Donbas insurgents. Second, it could deepen its military involvement by sending American military advisers, or even troops, to the frontline to bolster the Ukrainian army; but then Russia could call America’s bluff. Third, the United States could decide not to respond to Russia’s escalation given the geographical disadvantage and the limited strategic interests at stake. That would amount to backing down, abandoning Ukraine, and shredding the oft-repeated argument that American and European security hinges on the outcome of the Donbas war.
As hawks often do, advocates of arming Ukraine minimize the potential risks of their proposal while exaggerating the benefits that it will produce. On the one hand, they insist that they are “merely” calling for the U.S. to help Ukraine defend itself (they are actually calling for enabling Ukraine’s government to go on the offensive), but at the same time they believe that in doing so they will “raise the costs” for Russia to such an extent that it will significantly alter Russian behavior in and towards Ukraine. If the policy is as likely to change Moscow’s behavior as they say, it can’t be as low-risk as they claim, but if it doesn’t pose a serious risk it is probably going to have no positive effects at all. In the worst case, arming Ukraine sets them up for a disastrous defeat that the U.S. will have helped to enable.
The other flaw in the pro-arming case is that advocates of sending weapons to the Ukrainian government simply dismiss the negative consequences that are very likely to follow. They assume that the Russian government has a low tolerance for casualties, but they conveniently forget that it was Russian casualties in Tskhinvali that served as part of the rallying cry for the invasion of Georgia in the August 2008 war. The same people that called for pulling Ukraine out of Moscow’s orbit in 2014 didn’t anticipate the Russian response to Yanukovych’s overthrow, but they still think that Moscow will be more inclined to back down now when faced with new provocations. Western hawkish analysts and pundits have consistently underestimated how far Moscow will go in this conflict, so why should their assurances be trusted now? We should have learned over the last decade that Moscow is much more likely to respond forcefully to provocative Western actions than most of us have assumed, and that means that the U.S. should approach this conflict with greater caution instead of increased recklessness.
Menon and Ruger make another important point that tends to get lost in the debate on this question:
The case for arming Ukraine also tends to be made in a vacuum, never mind that what the United States does in Ukraine could determine what Russia does elsewhere. Moscow could respond by putting more pressure on the Baltics, acting as a spoiler in North Korea or Iran, or even arming the Taliban (that would be an ironic turn: in the 1980s, the United States bled the Soviets by arming the Afghan mujahideen). If these outcomes seem impossible, consider the United States’ awful record in foreseeing the effects of its military moves [bold mine-DL].
The explicit purpose of sending arms to Ukraine is to give their government the means to kill more Russians and Russian proxies. This may be dressed up in euphemisms by advocates (e.g., “raising costs,” “making them pay a price”), but that is what they expressly hope to achieve with this policy. If our positions were reversed, our government would not respond to the deaths of our soldiers and proxies by yielding to the preferences of the government that provided the weapons that killed them. On the contrary, our government would intensify its support for whatever policy that government was trying to thwart. It would be foolish to assume that the Russian government would respond differently. We should assume that they would respond both directly in Ukraine by increasing their support for separatists and indirectly by aiding our enemies in other wars. This last part was the point that analyst Michael Kofman made in a report from August:
Russia’s response to scattering Javelins among Ukrainian ground forces should factor into the decision, Kofman said.
“The Russians have a very clear policy of reciprocity, as we saw in the recent diplomatic purge. They see this as a premise of the U.S. wanting to kill Russians,” Kofman said.
“The answer to this won’t come in Ukraine.”