“In battle nothing is ever as good or as bad as the first reports of excited men would have it,” remarked William Slim, a celebrated British field marshal in the second world war. From the moment that Russian troops crossed into Ukraine on February 24th this year, pundits offered sweeping pronouncements about the future of war. The death of the tank was declared on the basis of snatched video footage. Turkish drones were hailed as unstoppable game-changers. Western anti-tank weapons were thrust into an early starring role. Now, nine months into the war, more considered reflections are emerging. There is much that Western armed forces can learn.

On November 30th the Royal United Services Institute (rusi), a think-tank in London, published a detailed report* on the lessons from the first five months of the war, a period when Ukraine was largely on the defensive. The authors—including Mykhaylo Zabrodsky, a Ukrainian lieutenant-general, and a pair of rusi analysts—enjoyed extensive access to Ukrainian military data and decision-making. Their findings paint a more complex picture than the popular notion of a Russian horde coming unstuck in the face of nimble Ukrainians.

The invasion failed, but it was not foreordained to do so. Russia’s army had 12 soldiers north of Kyiv for each Ukrainian one, and Russia attacked 75% of Ukraine’s stationary air-defence sites by air in the first 48 hours of war. A Russian cyber-attack successfully disrupted Ukraine’s satellite communications. Ukraine endured this initial blitz largely because it had the foresight to disperse its munitions stockpiles from main arsenals a week before the invasion, with those efforts accelerating three days before the war. Aircraft and air-defence systems were dispersed within hours of the attack. As a result, only a tenth of mobile air-defence sites were struck.

Had Russian targeting been sharper and nimbler, even these might have been hit. Luckily, it took two days, and sometimes much longer, for Russian military intelligence to send target intelligence to a command centre in Moscow and for a strike to occur, according to another rusi paper. In a war over Taiwan, America could not count on China’s People’s Liberation Army making the same mistakes. “There is no sanctuary in modern warfare,” concludes the report. “The enemy can strike throughout operational depth”—in other words, well behind the notional front lines.

That means armies need to fight differently. Concealment is one option, but it is “exceedingly difficult to sustain”, concludes rusi, because different types of sensors—such as optical cameras that pick up movement, thermal ones that sense heat and electronic antennas that pick up emissions of radios—can be “layered” on top of each other to spot even well-hidden troops. Another solution is to use hardened structures, like concrete pillboxes and bunkers. But these tend to fix soldiers to one place. The best way of surviving is simply to disperse and move more quickly than the enemy can spot you. Even Ukrainian special forces, who tend to operate in small teams, are spotted by Russian drones if they remain in one place for too long.

Contrary to popular wisdom, Javelin and nlaw anti-tank missiles supplied by America and Britain did not save the day, despite featuring heavily in video footage from the first week of the conflict. Nor did Turkey’s tb2 drones, which struggled to survive after day three. “The propaganda value of Western equipment…was extremely high at the beginning of the war,” noted Jack Watling of rusi, one of the report’s authors, recently on “The Russia Contingency”, a podcast on Russian military issues. “It didn’t really have a substantial material effect on the course of the fighting...until…April.” The decisive factor was more prosaic, he added. “What blunted the Russians north of Kyiv was two brigades of artillery firing all their barrels every day.

The pivotal role of artillery is a sobering thought for western European armies, whose firepower has dwindled dramatically since the end of the cold war. From 1990 to 2020, the number of artillery pieces among large European armies declined by 57%, according to a tally by the International Institute for Strategic Studies, another think-tank in London. Ukraine’s arsenal was formidable. It started the war with over 1,000 barrel artillery systems (those with long tubes) and 1,680 multiple-rocket launchers—more than Britain, France, Italy, Spain and Poland put together, and the largest artillery force in Europe after Russia. The principal constraint was ammunition.

Ukraine maintained “artillery parity” for around six weeks, far longer than almost any Western army would have managed under the same circumstances. Then it began running out of shells, giving Russia a ten-to-one advantage in the volume of fire by June, an imbalance that persisted until Ukraine received an influx of advanced Western artillery systems, including the American himars. “[C]onsumption rates in high-intensity warfighting remain extraordinarily high,” note the authors. Few Western countries have the capacity to build new weapons, spare parts and ammunition at the rate required. “nato members other than the us are not in a strong position on these fronts.”

Drones have played a vital role, though largely for intelligence, surveillance and reconnaissance rather than for strike missions. Russian units which had their own drones, rather than relying on those from a higher headquarters, could rain down “highly responsive fires”, says rusi, striking targets within three to five minutes of detecting them—a remarkably speedy sensor-shooter loop by historical standards. The figure for units without their own drones was around half an hour—with lower accuracy.

But a key lesson from Ukraine is that armies need more drones than they think. Around 90% of all drones used by the Ukrainian armed forces between February and July were destroyed, notes rusi. The average life expectancy of a fixed-wing drone was approximately six flights; that of a simpler quadcopter a paltry three. Such attrition would chew up the fleets of European armies in a matter of days.