• China, India, and the US have the largest active armed forces in the world.
• The International Institute for Strategic Studies compiled data about the world's militaries.
• The world's top armies spend hundreds of billions of dollars on defense each year.

The US military may lead the world in budget size and in the ambitions of its warfare technology, but there is one measure by which it is outsized by other nations.

Using data from the International Institute for Strategic Studies' 2026 Military Balance report, Business Insider ranked the top 25 countries by the size of their active armed forces during 2025 and listed their defense budgets that same year.

Active-duty force size is a tally of a country's uniformed troops: airmen, soldiers, sailors, special operators, and Marines.

Armies, in particular, depend on size to gain and occupy ground during armed conflicts.

Militaries can also be a tool of domestic repression. North Korea, for example, is one of the world's most repressive states, led by a dictator who has repeatedly threatened neighboring South Korea — and it also has one of the world's largest militaries.

The number of active-duty military personnel is far from the only factor that matters when comparing military power between countries, but it reflects latent power.

"Numbers have value, but there's a lot more to military capability," Mark Cancian, a senior advisor at the Center for Strategic and International Studies, a Washington, DC-based foreign policy and national security think tank, told Business Insider.

IISS, a London-headquartered think tank, counts active armed forces, reservists, and paramilitaries as separate categories in its analysis, showing a fuller picture of each nation's manpower.

Some countries have significantly more reservists than others — Vietnam has the largest number in the world, estimated at 5 million — but the quality and longevity of their expertise can vary between systems.

"When you look at some countries' reserve numbers, you're often looking at people who haven't trained in 10 or 20 years," Cancian said. "It gives you a big number, but their military value is questionable."

Even when accounting for all of a military's manpower, personnel is only one of the factors that can qualify a nation's military strength, which also includes equipment and readiness.

There's also the role of technologies in global warfare, the size and sophistication of air forces and naval fleets, amphibious capabilities for landing assault forces, command-and-control systems, and nuclear forces, all of which shape military power.

Still, comparing global manpower offers insight into how countries prioritize military power.

See how the world's largest militaries stack up in terms of active troop numbers.

Kazakhstan, Kyrgyzstan, and Kenya are seeking the return of citizens drawn into Russia’s war, Ukraine’s Foreign Intelligence Service (SZRU) said on 25 October. According to relatives and officials the agency cites, many of the men had gone to Russia for work, only to be tricked or forced into its army.

Russia fills its ranks partly with foreigners. In April, Ukraine’s military intelligence (HUR) said the Russian Defense Ministry plans to enlist at least 18,500 of them in 2026. Foreign recruits let the Kremlin put off hard choices about another mobilization at home, the Atlantic Council argued in May. Home governments have pushed back before, among them Ghana in August. The new statements show the limit of that pushback. Once a man is serving in Russia’s army, his government has to ask Russia to let him go.

Kyrgyz minister: contracts are forced in enlistment offices and jails

Kyrgyz Foreign Minister Jeenbek Kulubaev addressed the problem at a parliamentary committee on 13 October, answering lawmakers’ questions. He said Kyrgyz citizens in Russia are forced to sign contracts at military enlistment offices or in pretrial detention centers. If warned in time, diplomats try to stop the men from reaching the front.

Kazakhstan is compiling a list for Moscow

Kazakhstan is negotiating with Russia over citizens in the combat zone. Its Foreign Ministry said on 7 October that it was checking each hotline request. Once the checks are complete, the ministry said, it will send the compiled list to the Russian side.

SZRU separately cited unnamed relatives of one Kazakh worker. After he complained about working conditions, they said, he and other men were taken to an enlistment office and forced to sign contracts.

Kenya wants five men held by Ukraine treated as possible trafficking victims

Prime Cabinet Secretary Musalia Mudavadi, who also handles foreign affairs, gave lawmakers a count on 8 October. “The Ministry has records of 354 Kenyan nationals involved in the Russian-Ukraine crisis,” he told them. Families who petitioned Parliament dispute that number and put their own count at 841, Kenya’s The Star reported.

Ukraine holds five Kenyans captured while fighting for Russia, and Nairobi has already appealed to Kyiv over them. The government told Parliament it wants them treated as people who may have been trafficked abroad.

For Kenyans still serving in Russia’s army, the way out runs through Russian officers. Moscow informed Nairobi that unit commanders will consider requests to end military contracts case by case, the same government response said.

The U.S. Army is training Apache pilots to shoot down drones as militaries around the world assess the efficacy of 20th-century technologies in a new era.

© Lena Mucha for The New York Times