US Army Gen. Christopher Cavoli (right) talks with retired Gen. Robert Brown (left) during Eurosatory 2024. (Ashley Roque/ Breaking Defense)

EUROSATORY — Militaries the world over may be eagerly learning lessons from watching the fighting in Ukraine, but one ongoing debate emerged as a major theme at this year’s biennial defense conference in Paris: What’s the right balance between exquisite precision fires and “dumb” mass deep attack capability?

“It is a really tough one because historically, you know, our approach in NATO has been to use precision to defeat mass,” US Army Gen. Christopher Cavoli, the Supreme Allied Commander Europe, told an audience Wednesday. “Smaller numbers gotta beat larger numbers — use precision to defeat mass.”

Cavoli said that “most nations, on their own, would prefer to buy really exclusive, exquisite stuff that promises to win quickly.” Ukraine has used this approach successfully in “some pockets,” but there’s an element of delayed gratification.

“If one’s plan is to hollow out the backside of an enemy force so that it can’t continue, that’s a downstream effect of fires, and we have to wait for that effect to hit the frontline,” he said.

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But Cavoli said that “to get that time, typically what we do is trade space,” meaning the invading force is able to advance. That, he said, is an untenable strategy for Baltic nations who fear a potential Russian invasion and whose capitals can be within 125 miles from the Russian border.

“That’s just not the way things are going to be as long as Russia has the ability to put a large force on its own territory, right up against NATO’s borders,” he added.

To answer more quickly, if less accurately, there’s the option to attempt to meet mass with mass: lobbing scores of “dumb” 155mm rounds, for instance, at targets. (Ukraine has also relied heavily on non-precision fires, expending 155mm rounds at rates far less than the Russians but still more than they can keep in stock.)

But the debate goes beyond sheer numbers. One benefit of the “dumb” rounds, for example, is they are unaffected by electronic warfare. The same can’t be said for precision weapons relying on satellite guidance, argued an Estonian military official here.

“Sometimes expanding 60 rounds and hitting with one or two of them is better than expanding one or two [precision] rounds that cost the same amount but they get either jammed and fall off the target or get shot down on the way to the target,” artillery officer Maj. Tatsi Tanel said at a different panel Wednesday.

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Tanel was echoing US Army Europe and Africa Commander Gen. Darryl Williams, who last month asserted that traditional cannon-based mass fires are still the best solution in an EW environment. His comments came at a time when precision munitions are experiencing higher failure rates, and there have been multiple reports of Russian forces jamming or spoofing munitions that rely on GPS.

Then again, the problem with mass fires is the mass, meaning its use requires a healthy supply line, which has emerged as a significant problem for Ukraine’s backers in Europe and in the US, as industries have struggled to ramp up ammo production.

In the end, Cavoli and Tanel appeared to advocate for the mixed use of precision and non-precision munitions — in Tanel’s words, using precision weapons at times but also employing mass artillery fire to take out “important targets in depth with unguided rounds.”

Speaking to an audience Tuesday in Paris, the head of the US Army’s Program Executive Office Ground Combat Systems, Maj. Gen. Glenn Dean, agreed with the mixed option.

“You have got to have precision … but have to maintain mass,” he said. “And the ability to do mass is not just in the ability of the gun [to answer] ‘How fast can I sling 155mm shell from a cannon?’”

But Dean cautioned that the problem goes beyond simply moving more rounds to the front line. The opponent force, he said, will be laser focused on not only destroying the actual launcher but the resupply node. That is why the US Army is currently talking with industry about ways to automate the supply chain, while also discussing better platform protection options, and automation for higher rates of fire.

The End Of Towed Artillery?

Requirements and acquisition leaders inside the US Army have been grappling with all the issues Cavoli, Williams and Tanel posed, including as part of a recently completed tactical fires study. Details about the results of the study remain under wraps but details have been slowly trickling out, suggesting the usefulness of towed artillery, for one, is falling by the wayside.

In Paris, Dean put it more bluntly: “Towed artillery is done,” but he said there may be a place for a “certain small amount” for forced entry formations  .

“It will not survive. It can’t displace. It can’t move. It can’t emplace quickly enough to be survivable on the modern level,” the two-star general added.

While towed artillery may be on its way out, at least for the US Army, the service is eyeing several new artillery options for industry. After shutting down work on its Extended Range Cannon Artillery (ERCA) platform prototype, they are calling on companies to demo their self-propelled howitzers. Also new, they are looking for options for wheeled and tracked autonomous fires options.

“I don’t know which one, but we are open to everything,” he said.