A brutal artillery battle: that’s what the latest phase of Russia’s war on Ukraine has become. Vladimir Putin failed in his original goal of seizing the entire country swiftly, beginning with the capital of Kyiv, and installing a puppet government. When Ukrainian resistance prevented that, Putin shifted to a smaller, more achievable objective: establishing complete control over two eastern provinces, Luhansk and Donetsk, which border Russia and are jointly known as the Donbas region. That’s where the war is being fought now, with an uncertain outcome. Victory will depend on who wins the artillery battle. Russia has more blunt firepower; Ukraine has more precise, longer-range weapons — or at least it will have them when more NATO supplies reach the frontlines.

Seizing the Donbas provinces would complete a project Russia began in 2014, when it captured parts of that region, plus the Crimean peninsula. Establishing complete control now would give Russia a secure “land bridge” from its own territory to Crimea, as well as a base to continue destabilizing Ukraine. From there, it could launch further attacks and seize still more territory after regrouping and resupplying its battered army. Putin’s ultimate goal is the same as it has been since the beginning: seize as much Ukrainian territory as possible, terrorize the population, eliminate the country’s independence and turn Ukraine into a subordinate satellite.

Ukraine’s goals are to prevent that conquest, retake as much land as possible, reestablish complete sovereignty over its territory and prevent future attacks and destabilization. Its immediate, minimal goal is to push Russia back to the territory it held in February, before Putin launched this unprovoked war.

What goals do NATO and the United States have? Those are crucial to the war’s outcome since Ukraine has the will to fight but not the arms, ammunition and battlefield intelligence. Ukraine’s only hope of pushing back Russia is to receive them — immediately and in vast quantities. How vast? Well, estimates are that the Russian army is launching 70,000 shells per day on the outnumbered Ukrainians. That barrage is killing some sixty to 200 Ukrainian troops every day, pulverizing cities and the civilians within them and leading to slow accretion of territory in the east. Western artillery can counter that since it has longer range than Russian guns and is far more precise. But, to do so, the weapons and ammunition must reach the front lines in large numbers.

Ah, there’s the rub. NATO has been supplying those essential resources but the pace has been far too slow. US defense secretary Lloyd Austin (himself a former general) has publicly pledged to get those supplies to Ukrainian forces and is vigorously supported by most NATO members, led by Poland, which has been supplying weapons themselves. But not all NATO members are so enthusiastic. Germany and France have been reluctant to support this full-scale effort. Instead, they have tried to negotiate with Putin behind Ukraine’s back (and without its permission). Not surprisingly, they have also been exceptionally slow to provide Ukraine with the weapons it promised and resisted the transfer of some weapons from other NATO members.

Why are Paris and Berlin so reluctant? One reason is their fear that providing more weapons would not only prolong the war but risk drawing NATO members into direct confrontation with Russia. All NATO members share that fear of direct, lethal combat between NATO and Russian troops. But France and Germany are considerably more risk-averse than other members — and more willing to strike compromise deals with Russia to avoid it. Second, France and Germany seem to think that, ultimately, Ukraine cannot retake the territory it lost. Their view is that the Ukrainian regime, led by Volodymyr Zelenskyy, should recognize that harsh reality and strike a deal with Moscow conceding those losses. Henry Kissinger has reached essentially the same conclusion.

There are two problems with that approach, which is why the West has not adopted it. First, the Ukrainians themselves violently reject this kind of compromise. Their losses have been too large, Russia’s crimes against humanity too cruel and too visible. Faced with those realities, no government in Kyiv could survive if it permanently ceded territory to Russia. It might survive a temporary, “standstill” agreement but not one that permanently ceded sovereign territory. Remember, one major, unexpected consequence of Russia’s unprovoked aggression is that it has forged a nation in opposition. Modern Ukraine has been forged in Russian fire. Russia cannot hold any territory it conquers without a permanent army of occupation, vulnerable to constant sniper attacks.

Nor is Moscow ready for such any compromise agreement, at least not yet. It wants to wait until its army has consolidated control in the Donbas. It will never withdraw its army from territory it holds, any more than it withdrew the Red Army after 1945. Second, any standstill agreement would be highly unstable in both the short- and medium-term. In the short term, it could be toppled by the inevitable provocations that plague ceasefires. In the medium term, it would likely be toppled because neither side accepts the solution. After any agreement, both sides would be regrouping and resupplying their forces, getting ready to fight again.

What will happen next? That depends almost entirely on whether the US, Britain and key NATO partners are willing and able to get massive resupplies to the frontlines — and get them there quickly. They need to do far more than they have done over the past two months, as the artillery battles began. The war for the Donbas depends on NATO’s success in doing more. The future of Ukraine depends on it. So does the West’s deterrence against future Russian aggression. If Russia wins this battle, who expects them to stop there?