Giving Ukraine heavy weapons does not mean NATO is at war with Russia

As with the Soviets in Vietnam, providing arms is not the same as fighting

Apr 17th 2022

A BILLION EUROS ($1.1bn) goes fast when you are fighting a war. But Germany’s announcement on April 15th that it would give around that sum in additional military aid to Ukraine may at least soften criticism of its failure to send tanks. It is part of a recent wave of pledges to provide Ukraine with heavy weapons. Two days earlier America promised $800m in new aid, including armoured personnel carriers and helicopters. Britain is sending armoured patrol vehicles and anti-ship missiles, while the Czech Republic has delivered mobile rocket-launchers and T-72 tanks from its old Soviet stockpiles. Slovakia, which has already sent Ukraine an S-300 anti-aircraft system, has said it might also provide MiG-29 fighter jets (pictured), a Soviet model that Ukrainian pilots know how to fly.

In early March, America scotched a similar offer of MiG-29s from Poland, for fear it might invite reprisals from Russia, and thus drag NATO into the war. Emmanuel Macron, France’s president, was more explicit still, suggesting that donations of heavy weapons might prompt Russia to label NATO a “co-belligerent”: a party to the conflict, and thus a legitimate target under the laws of war. Now, America says it has no objection to Slovakia’s offer. Early in the conflict Ukraine’s friends mainly stuck to giving it small arms and portable anti-tank and anti-aircraft missiles. As it has grown clear that the war will be a long one, they have become willing to supply it with complex systems that require months of training. Russian war crimes have also helped convince them to give Ukraine the heavier gear it needs to recapture occupied territory, and to help it shift from old Soviet kit to NATO-standard weaponry which could be maintained and armed more easily.

Yet the shift to heavier weapons provokes anxiety in some quarters, especially in Germany, which has suspended an offer of Marder infantry fighting vehicles, after its defence ministry said it had too few to give any away. Sahra Wagenknecht, an MP from the Left party, said sending Marders would make Germany a Kriegsteilnehmer (“participant in the war”). Even Robert Habeck, the relatively hawkish climate minister, says Germany has “a responsibility not to become a target of attack ourselves”. All this seems to stem from a fear that delivering heavy weapons heightens the likelihood of a direct conflict between Russia and NATO.

From a historical perspective such worries seem misplaced. Take the offer of MiG-29s. During the war in Vietnam, dozens of American planes were shot down by North Vietnamese fighter jets furnished by the Soviet Union. In addition to aircraft, North Vietnam received vast numbers of tanks, missiles and artillery pieces from its Soviet and Chinese patrons, and used them to kill thousands of American soldiers. Both sides worried that this proxy war could escalate into a direct conflict between nuclear powers. Yet it never did.

The war in Ukraine presents a similar situation, with the roles reversed. This time it is Russia that is fighting a smaller state whose forces are being equipped and trained by America and its allies in NATO. Russia has warned NATO that it may strike countries that supply or aid Ukrainian forces, and has even hinted it might use nuclear weapons.

From the perspective of international law, experts say, Russia’s position is unjustified. “Supplying weapons, including heavy weapons, would not in and of itself make a country a party to an armed conflict. That would require more direct involvement in military operations,” says Adil Haque, a professor at Rutgers Law School and the author of “Law and Morality at War”.

This has not always been the case. International law, as it developed in Europe beginning in the 17th century, required countries that wanted to stay out of others’ wars to observe strict neutrality. That meant they had to trade equally with both sides of a conflict, as Oona Hathaway and Scott Shapiro, professors at Yale Law School, explained in a recent article. Supplying arms to one side only, or favouring its trade, could make their ships fair game for attack by the other.

But this law of neutrality was designed for a world where war was an accepted tool of statecraft. That changed with the adoption of the Kellogg-Briand Pact in 1928, which made it illegal to attack another country unprovoked—a principle later enshrined in the UN’s charter. The charter recognises that states have a right to self-defence, and that other countries can join in “collective self-defence” to help them. States are allowed to give military support to victims of aggression, or to impose sanctions on the aggressor, without affecting their own neutral status. Indeed, when the UN Security Council condemns an act of aggression, that resolution is legally binding on all member states.

In Ukraine no such Security Council resolution has been adopted—but only because Russia, a permanent member, vetoed it. The UN General Assembly overwhelmingly condemned the invasion. As for states becoming co-belligerents, the bar is even higher, argues Michael Schmitt of the United States Military Academy at West Point. German supplies of arms to Ukraine do not make Germany a party to the conflict with Russia because “there are no hostilities between the States concerned”—their soldiers are not killing each other.

To many analysts, legal definitions of neutrality or co-belligerency seem irrelevant. If Vladimir Putin, Russia’s president, decides not to target NATO convoys supplying arms to Ukraine, it will not be because of the persuasive force of international jurisprudence. Yet by the same token, it is naive to imagine that supplying only portable missiles (which, after all, still kill Russian troops) would lead Mr Putin to exercise restraint. “If Russia wants to feel provoked and attack NATO it will do it, independently of whether we have delivered tanks,” says Claudia Major of the German Institute for International and Security Affairs.

Others think that if supplying heavy weapons increases the risk of a direct conflict, it is mainly because they make more inviting targets. Portable anti-tank and anti-aircraft missiles can be hidden and transported in commercial trucks. “To move tanks and artillery you have to put them on railway wagons, and that is more vulnerable to Russian air power, long-range artillery or cruise missiles,” says Dick Zandee, a defence expert at the Clingendael Institute in the Netherlands. That could change the balance of risk and reward if Russia contemplates strikes that could kill NATO personnel, whether in Ukraine or on NATO territory. (In practice, Russia has shown little ability to track and strike moving targets even in eastern Ukraine.)

Still, it is wrong to dismiss the legal aspects of co-belligerency entirely: they help prevent a conflict escalating to nuclear war. When America and other NATO countries rule out putting boots on the ground in Ukraine, they emphasise such a step would make them parties to the conflict. This, Mr Haque thinks, is a useful way to draw red lines between nuclear powers. “America is using these rules of international law to signal to Russia that we will come up to a clear red line but not cross it. I think Russia understands that signalling,” he says. “But they will try to contest the American interpretation of those rules and invent their own red lines—not based on law—to serve their aims.”

This game of red lines took place in Vietnam too. The scale of Soviet and Chinese supplies of heavy weaponry to the North Vietnamese dwarfs anything imaginable in Ukraine. After the Sino-Soviet split in 1964, the two communist powers competed with each other in arms deliveries. By the end of the war, in 1975, they had sent North Vietnam upwards of 500 aircraft (including 180 fighters), 2,500 tanks and tens of thousands of artillery pieces. Soviet trainers often pressed the buttons on anti-aircraft missile systems that shot down American fighters over Hanoi. Russian historical propaganda websites still boast of this, even as Russia claims to be outraged by Western arms deliveries to Ukraine.

Yet America never accused the Soviets or Chinese of being co-belligerents, and the nuclear powers never came close to direct conflict. American bombers avoided Soviet freighters: when US Air Force pilots accidentally strafed one in 1967, they were court-martialled. America was restrained not by international law but by the fact that bringing the Soviets or Chinese into the war would not have been in its interests.

That will be the decisive factor for Russia in Ukraine, too. “If Russia wanted the conflict to spill over and drag us in, it would have already succeeded in doing that,” says Kalev Stoicescu of the International Centre for Defence and Security, a think-tank in Tallinn, the Estonian capital. “They want to frighten us but not get us directly engaged. They can barely manage Ukraine, let alone NATO.”