Think tank simulation predicts “huge” losses on all sides, including the US, if China invades Taiwan

A wargame simulation of a full-scale Chinese invasion of the autonomous island nation of Taiwan predicts “heavy losses” for all parties likely to be involved, including the United States and Japan.

The Center for Strategic and International Studies (CSIS) has simulated a 2026 Chinese invasion of Taiwan exactly 24 times, drawing on historical data and operational research. Simulation events are included in the file Comprehensive report Released Monday.

In most scenarios, an alliance of the United States, Japan, and Taiwan defeated China after three or four weeks of fighting—but with the loss of dozens of ships, hundreds of aircraft, and tens of thousands of troops.

Mark Kancian, a senior advisor with the CSIS International Security Program and author of the report, told The Hill that the big idea from the simulation is that Taiwan can be preserved as an independent country.

“But the cost is too high,” he added.

In the report, Kansian recommended policies and efforts to deter a future invasion, noting that even if war was deemed too risky for China, the nation still contemplated direct conflict.

“Although our analysis indicates that the United States and Taiwan will prevail and take a heavy toll, it is possible to imagine that the Chinese view it differently,” Kansian explained. “That’s why we recommend strengthening deterrence so we don’t get into this situation in the first place.”

In recent years, China has increased its aggressive rhetoric against Taiwan, the independent democracy that separated from the mainland in 1949. However, the ruling Chinese Communist Party sees the island as part of its territory.

The United States adheres to the One China principle, which states that Taiwan is part of China, but is committed to informal relations with the island nation, including the supply of arms to Taipei.

At the same time, the United States is also bound by “strategic ambiguity” in the event of a Chinese invasion, making it unclear how US forces will respond.

CSIS wargame simulations modeled a “Taiwan stands alone” approach, assuming Taipei had no support from the US or Japan – and ended up with a quick Chinese takeover. Unlike the US arming Ukraine against Russia, China can block US supplies to the island.

The simulation relies on historical information and data of ground combat operations during an amphibious invasion, as well as speculative models of missile attacks based on the size of the warhead and the amount of area it will cover upon impact.

The games include a wide range of scenarios, considering cases where China does better than expected or performs poorly in the invasion.

While the United States and Taiwan prevail in most scenarios, there are some conditions for success, according to CSIS, including that Taiwan must remain on the line and that American forces must have access to bases in Japan.

The model predicts 19 scenarios in which Japan will be involved in the conflict. Japan is ambiguous about defending Taiwan, but Prime Minister Fumio Kishida announced last year a Historic shift from defense-only strategy and a significant increase in its annual defense spending.

Researchers said that although China has more presence in the South China Sea, the United States still has the most powerful military around the world, and many pessimistic conditions must be fulfilled in order to lose a military war.

“What China is trying to do is very difficult,” Kansian said. “Amphibious assault on a hostile beach – though [Taiwan Strait] It’s 100 miles wide – it’s very, very hard.”

However, the simulation found that any direct conflict between China and the United States would destroy Taiwan and potentially weaken the United States on the world stage.

There were some limitations to the model, including that it rates China based on where its military forces will be located in four years. China is pushing to build a “world-class” military in the next two decades and is with the aim of quadrupling its nuclear arsenal in the next 13 years, according to the Department of Defense.

CSIS also did not simulate a scenario in which nuclear weapons are used, which would mean an entirely different kind of war, or the possibility of a Chinese blockade of the island.

Another possible scenario is that Taipei quickly surrenders to China and offers little resistance, or the war lasts more than three or four weeks, which means more losses.

Matthew Kancian, who designed the conflict with his father Mark and has simulated other war games at the US Naval War College, said the simulation does not “call” for the United States to “defend or not defend” Taiwan.

“It just shows the cost and potential outcomes of these options,” he said.