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The world is running out of soldiers

Wars are getting more common and militaries are building up. There’s just one thing missing.

Ukrainian Army Trains New Recruits Amid Efforts To Boost Fighting Force
Ukrainian Army Trains New Recruits Amid Efforts To Boost Fighting Force
Young recruits undergo military training at a recruiting center in Kyiv, Ukraine, on April 9, 2024.
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Joshua Keating
Joshua Keating is a senior correspondent at Vox covering foreign policy and world news with a focus on the future of international conflict. He is the author of the 2018 book, Invisible Countries: Journeys to the Edge of Nationhood, an exploration of border conflicts, unrecognized countries, and changes to the world map.

A war between the United States and China would involve the kind of military manpower the world hasn’t seen in decades. As a point of contrast, around 156,000 troops landed on the beaches of France during the Normandy invasion in 1944, which was commemorated by world leaders earlier this month. Some experts estimate that if China were to try to invade Taiwan — the most likely flashpoint for a superpower confrontation — it might need as many as a million. If the US were to defend the island, according to some estimates it might suffer as many as half the number of casualties in just the first three weeks of fighting as it did in 20 years of war in Iraq and Afghanistan.

The last time the US fought wars anywhere close to this scale, many of those fighting were not there by choice: the military draft only ended in 1973, as American involvement in the Vietnam war was winding down. That conflict involved some 2.7 million American servicemembers in total, more than 58,000 of whom were killed — around 30 percent of whom were draftees.

A report released on Tuesdayby the Center for a New American Security (CNAS), a DC-based defense think tank, looked at what might happen if the American government once again felt a draft was necessary to provide for the nation’s security. For military planners, its conclusions are not encouraging.

In a tabletop wargaming exercise — in which experts are asked to anticipate how a given military scenario might turn out — participants including military officers, Pentagon staff, and academic experts were given the task of raising a force of 100,000 conscripted US soldiers in 193 days for a war with China. (One scenario involved a war over Taiwan; another, significantly less plausible one, involved a Chinese attack on the West Coast.) The most “successful” groups in the exercise found they’d likely only be able to raise half as many of the 100,000 needed soldiers; most groups raised far less.

Some of the factors complicating their efforts were simply logistical: The Selective Service System has estimated it will take 500,000 induction notices to produce 100,000 draftees. But by US law, those notices would be sent by mail to the address that draftees — which include all 18- to 25-year-old men living in the US — used to register for selective service when they turned 18. Many of these letters would probably not reach their intended recipients.

There would almost certainly be legal challenges to the draft, as well as significant public protests, while some number of draftees would apply for conscientious objector status or dodge it altogether. (An estimated 300,000 Americans either illegally dodged the draft during the Vietnam War or deserted from the military.) Many, if not most, might simply not be eligible for service: Pentagon studies have found that around 77 percent of young Americans would not currently qualify for military service due to being overweight, using drugs, or having other physical or mental health issues.

The military would also have to ensure that it had the equipment, facilities, and training resources needed to absorb these raw recruits so quickly. This was an issue in the early days following Hamas’s October 7 attacks, when the Israel Defense Forces called up a record 300,000 reservists only to be quickly overwhelmed by complaints about insufficient facilities, equipment, food, and other logistical bottlenecks.

Given the cultural and political upheaval that ultimately caused the draft to be scrapped toward the end of the Vietnam War, a return to mass conscription is not an option most US leaders would prefer to contemplate. But the CNAS report makes a stark case that US leaders need to at least consider scenarios where it would become a necessity: “US lawmakers, policymakers, and military leaders must assume that if a draft were called, it would be absolutely necessary. And if it is necessary, it must work.”

“We have been so successful at deterring major power conflict for the past 75 years that we have started to consider them a relic of the past,” Katherine Kuzminski, author of the report and director of CNAS’s military, veterans, and society program, told Vox. “Now, every country is having to think about what happens when you have a no-kidding, existential threat on your borders.”

But while we may live in a world in which the number and severity of armed conflicts are increasing again after decades of decline and in which countries around the world are ramping up their military spending, there’s one resource nearly all major militaries seem to be short of: people to actually fight those wars.

War without soldiers

In the United States, the Army is slashing its ranks by thousands of positions amid chronic recruiting shortfalls. In Europe, despite military spending increases since the war in Ukraine, the shortfalls are, if anything, even worse: Germany’s military has been shrinking for years despite a major recruiting push, while the UK may soon decommission four warships because of a lack of sailors to sail them. Despite a military buildup prompted by concerns about China, Japan’s Self-Defense Forces are falling short of their recruitment goals. Even China, which has the world’s largest military by people-power — with some 2 million active personnel — is struggling to recruit the skilled high school graduates it needs to operate its increasingly advanced weaponry. There’s an active debate among defense analysts about whether China even has the personnel needed to pull off an invasion of Taiwan.

In this context, more national leaders are starting to gingerly approach the issue of conscription. Germany’s defense minister recently presented a plan for a form of limited military conscription based on the systems now used by Scandinavian countries, which conscript some, but not most, eligible young people based on defense needs. Britain’s Conservative Party has included a plan for mandatory national service — with military and civilian options — in its platform for the country’s upcoming election. In the United States, the Washington Post recently reported some allies of former President Donald Trump’s campaign have suggested that some form of national service might be introduced if he is elected.

Whether any of these initiatives will go anywhere is hard to predict. Britain’s Conservatives are widely expected to lose, and Trump himself, who avoided service in Vietnam due to a diagnosis of bone spurs, dismissed the Post report as “fake news.” But in an era of so-called “great power conflict,” the question of who will actually be fighting the wars of the future will only become more important.

Lessons of Ukraine

The reason for the sudden resurgence of global interest in soldiers and conscription isn’t a mystery. The war in Ukraine, with its trench lines, tank battles, and artillery duels, marks a return to the sort of warfare that many had hoped was consigned to the dustbin of history.

For instance, the year-long Battle of Bakhmut, in which Russian forces — primarily from the semi-private Wagner Group — eventually succeeded in taking a small eastern Ukrainian city, was Russia’s bloodiest battle since World War II. More than 19,500 fighters were killed, according to a recent independent media investigation. That’s more troops killed in a single long battle than the Soviet Union lost in its decade-long war in Afghanistan in the 1980s.

Finding troops for the “meat grinder” in Ukraine hasn’t been easy for the Russian government. Russia does conscript soldiers every year, but conscripts generally can’t be deployed outside Russia. In the fall of 2022, the Kremlin declared a “partial mobilization” meant to raise 300,000 troops for the military. But more than twice that number are believed to have fled the country to avoid the draft.

Since then, however, Russia has managed to stabilize its manpower situation. It has done this in part by offering large signing bonuses that exceed average annual salaries in many remote and impoverished regions of Russia, and by granting pardons to prison inmates. (Pardoned prisoners made up the bulk of the fatalities in Bakhmut.) These tactics have largely kept the public backlash to the hundreds of thousands of casualties manageable.

The worries about personnel are far more acute in Ukraine, which has a democratic political system and about 100 million fewer citizens than Russia. The long lines that formed outside recruiting centers immediately after Russia’s full-scale invasion in 2022 are a thing of the past. Today, there are desperate shortages of Ukrainian troops on the front lines.

The average age of these soldiers is over 40 — shockingly old by global standards. President Volodymyr Zelenskyy recently signed a controversial law to lower the age for draft eligible men from 27 to 25. (The average age of an American GI in Vietnam was 19.) The government has resorted to a number of carrots (giving volunteers the right to choose their own battalions) and sticks (highly unpopular street patrols to find young men avoiding the draft) to replenish the ranks. And like Russia, Ukraine is also now recruiting prison inmates to serve.

Another similarity to Russia: Ukraine was in a state of precipitous population collapse even before the war, thanks to a combination of plummeting birth rates and out-migration. Its population declined from 51.5 million when it became independent in 1991 to just 37 million in 2019. Add to that the more than 6 million people who fled the country after the outbreak of war, those currently in the military, those killed or seriously wounded in the war, and those who’ve turned to black market employment in order to avoid conscription, and it’s no surprise that Ukraine’s civilian economy is facing serious labor shortages.

The war has presented Ukrainian leaders with an agonizing choice that goes even beyond the brutal prospect of sending thousands of young people to their deaths: Fighting for their national survival today might require decimating the nation’s already grim demographic future.

Grayer world, grayer wars

Demography is also on the mind of military planners in rapidly aging East Asia, which is furthest along the global trend toward lower fertility rates. With the ever-present risk of a major war with neighboring North Korea growing, South Korean men have to perform at least 18 months of military service — and at least among democracies, it’s one of the toughest countries to avoid the draft. Even members of K-Pop supergroup BTS have to put in their 18 months.

But the country is also facing some stark population math. To maintain current troop levels, South Korea needs to enlist or conscript 200,000 men per year. But if current birth rates continue, in 20 years there will only be about 125,000 men available per year to fill those spots.

South Korea has one of the world’s fastest aging societies, but it’s hardly an outlier. Two of the regions with the fastest falling birth rates — East Asia and Eastern Europe — are also the places where risk of interstate war or superpower conflict may be highest right now.

In China, demographic decline is further compounded by the legacy of the country’s one-child policy. A high-casualty war — which China has not fought since its conflict with Vietnam in the 1970s — would devastate many families in a society where lone adult children are often expected to provide for their aging parents. Perhaps in recognition of this concern, the People’s Liberation Army amended its policies to allow parents as well as spouses to claim death benefits for a soldier killed in the line of duty.

There might appear to be a bright side to all this. Not so long ago, some theorists were predicting a “geriatric peace”: societies with fewer available soldiers as well as older — therefore, presumably, less aggressive — populations might simply be less likely to start wars.

But the recent actions of Russia — where population decline is only slightly slower than in Ukraine — provide a powerful counterexample to that theory, not to mention the rising tensions and territorial conflicts in fast graying East Asia. The calculations of aggressive leaders like Vladimir Putin or Xi Jinping might just as easily be explained by what international relations theorists call “power transition theory”: the idea that governments will try to lock in military gains before their power starts to decline.

In other words, looking at decades of population decline to come, China’s Xi might decide that now is the moment to act in Taiwan, while he still has the troops to take it.

Andrew Oros, a professor of political science at Washington College who is writing a book on the security implications of East Asia’s aging societies, suggests that we may be seeing what he calls “dual graying” of conflict in the region: As societies age, they may be more likely to engage in so-called “gray zone” tactics — sabotage, propaganda, hacking, deniable attacks by unofficial militias and dual-use fleets — rather than all-out war. “This kind of gray conflict is something that older states are still very capable of doing,” Oros told Vox. “You don’t necessarily need to be fully able-bodied to fight a cyber war.”

Dulce et decorum est?

It’s not just that the pool of available soldiers is getting smaller. Those in that pool are less willing to join up than ever. Polls show young people around the world are becoming far less willing to fight for their country. Young Americans have far more negative views of the military as an institution than older ones.

Retired Army Lt. Gen. Benjamin Freakley, who supervised recruiting as commander of the Army’s Accessions Command, said one challenge is an anti-establishment mood in society at large, one that has even infected feelings about the military — an institution that long had wide support from Americans, whatever their politics. “There’s something of a loss of confidence in institutions across the board — courts, the government, the media, and the military,” Freakley told Vox.

When those feelings are paired with what is now a period of relatively high employment and higher wages in even low-skills sectors in the private economy, and the idea of arduous and potentially dangerous military service can look less appealing. It’s not a coincidence that Russia has been doing the bulk of its conscription in poorer, more remote regions of the country where the private sector can’t compete with military bonuses.

This trend holds even in some countries facing imminent military threat.

Taiwan recently extended compulsory military service for its citizens from four months to a year, but service is widely unpopular among many young Taiwanese and the government has struggled to expand its roughly 169,000-strong military.

A recent Carnegie Endowment poll shows that in Ukraine, a significant generation gap has opened up in attitudes toward the war. Ukrainians over 60 are about 20 percent more likely to say that Ukraine is winning the war and that it should fight until it liberates all its territory than those between 18 and 25 who would be more likely to do the actual fighting if the country began drafting more aggressively.

Jennifer Sciubba, a population demographer who focuses on defense issues, told Vox that “when you have a larger pool [of potential recruits or conscripts] to draw from you have to worry less about cultural shifts. It becomes a great issue in countries where the shift toward smaller populations is more pronounced.”

Uncle Sam wants you

A range of policy changes are being considered in light of these trends. Some Asian countries are loosening age and height requirements to expand the pool of potential recruits or conscripts. Australia, dealing with its own recruitment woes, is considering allowing foreign nationals to serve in its armed forces for the first time. At a recent panel at the Center for Strategic and International Studies, Gen. James Slife, vice chief of staff of the US Air Force, said his commanders were looking at loosening some restrictions, such as requiring airmen to have driver’s licenses. (Gen Z-ers are far less likely to drive.)

The elephant in the room when it comes to discussion of manpower is gender. Israel may be the best-known example of a country with universal (with some notable exceptions) military service for both men and women. Norway and Finland are among the few countries with selective service systems that draft women as well as men, though Denmark recently joined them. Taiwan only recently rolled out plans to allow women to register for reserve training.

In the United States, where women are no longer excluded from combat roles in the military, the Supreme Court has rebuffed several legal challenges to the all-male Selective Service System.

But CNAS’s Kuzminski suggests that this is an issue for the government to deal with now, rather than when a wartime draft actually becomes necessary.“The legal underpinning for the all-male registration law is on pretty shaky ground,” she said. “It’s not about the social policy side of things. From our perspective, it’s about the fact that you cannot afford to lose a week, a month, two months, while this gets moved up through the courts.”

Then there’s the question of whether the wars of the future will be fought by humans at all. The Pentagon recently announced plans to build thousands of cheap drones as a means to, in the words of Deputy Defense Secretary Kathleen Hicks, “overcome [China’s] biggest advantage, which is mass. More ships. More missiles. More people.”

Gen. Nick Carter, former chief of the UK’s Defense Staff, predicted in 2020 that his country might someday “have an army of 120,000, of which 30,000 might be robots.” (The country currently has 130,000 servicemembers, all human.)

Freakley, who commanded US combat troops in Iraq and Afghanistan, was skeptical of the idea that “mass” could be achieved through autonomous systems alone, pointing out that similar claims had been made in previous generations by advocates of airpower. “There’s always a balance between manpower and technology,” he said, “but what history has shown us in warfare is that if you want to control another nation, you’ve got to put boots on the ground.”

But finding young people to put into those boots is only becoming more challenging.