The Pentagon’s annual report on Chinese military and security developments warns this week that China is building up a fleet of long-range nuclear-capable bombers and is “likely” training its pilots to attack American targets.

The relevant section of the report concerns China’s “overwater bomber operations,” which have rapidly expanded over the past three years. The Pentagon sees Chinese pilots “gaining experience in critical maritime regions and likely training for strikes against U.S. and allied targets.”

The People’s Liberation Army Air Force (PLAAF) is currently the largest air force in Asia, and the third-largest in the world. Since 2017, new commander Lt. Gen. Ding Laihang has focused on developing a capacity for projecting long-range air power comparable to the U.S. Air Force.

“The PLAAF continues to modernize and is closing the gap with the U.S. Air Force across a broad spectrum of capabilities, gradually eroding the United States’ longstanding significant technical advantage,” the Pentagon report cautioned.

U.S. analysts are particularly concerned about the latest evolution of China’s H-6 “Badger” bomber, the H-6K, which is capable of launching from Chinese airbases and hitting Guam with standoff precision weapons. The PLAAF is also working on midair refueling techniques and might be able to field nuclear-capable stealth bombers as early as 2025.

China’s use of militarized islands in the South China Sea as bases for long-range bomber activity is noted as an area of particular concern. “H-6s could, if deployed to airfields in the Spratly Islands, extend their range through the Balabac Strait into the Celebes Sea or through the Sunda or Malacca Strait to fly into the Indian Ocean,” the report stated.

To secure their claims in disputed waters, the Chinese employ a unique naval command that has been given little attention until now, the People’s Armed Forces Maritime Militia (PAFMM). The Pentagon judged the PAFMM to be the “only government-sanctioned maritime militia in the world.” The militia plays a “major role in coercive activities to achieve China’s political goals without fighting.”

In other words, the maritime militia intimidates civilian vessels from other nations that attempt to access waters claimed by Beijing, with just enough operational separation from the regular military to give the Chinese government political cover. China portrays its militia vessels as fishing boats that just happen to have armored hulls and ammunition storage bays.

U.S. defense analysts are concerned that China will not only militarize the South China Sea, but nuclearize it.

“In 2017, China indicated development plans may be underway to power islands and reefs in the typhoon-prone South China Sea with floating nuclear power stations,” the Pentagon report noted. “Development reportedly is to begin prior to 2020.”

The Chinese air force has invested considerable effort in demonstrating that its bombers can hit Taiwan. “Depending on the weapons load, potential future H-6 missions could include anti-ship or shorter-range strikes targeting eastern Taiwan from all directors or supporting a blockade,” the Pentagon anticipated.

“Currently, such missions are vulnerable without defense counter-air support provided by fighters traveling along the route with the bombers,” the report added. China is notably interested in developing that type of fighter support and has conducted at least one significant exercise in the Western Pacific involving bombers, fighters, and an early-warning control aircraft comparable to an American AWACS formation.

China’s battle plan for Taiwan is said to include plans for fighting the American Navy and Air Force as well: “Should the United States intervene, China would try to delay effective intervention and seek victory in a high-intensity, limited war of short duration.”

The Chinese have an abundant supply of both surface-to-air missiles and ground-launched ballistic missiles that can attack ships across the western Pacific. They are believed to possess between 75 and 100 intercontinental ballistic missiles capable of hitting targets in Europe and the continental United States. As a graphic provided in the Pentagon report illustrates, China is capable of peppering the waterways around Japan, Taiwan, India, and the South China Sea nations with anti-ship missiles and holds a large inventory of weapons that can hit ground targets across all of those countries.

In space, the Chinese military is working on jammers, missiles, and kinetic weapons that can kill American satellites. The first stage of a Chinese space station is expected in orbit sometime in 2019.

The Pentagon wryly notes that while Chinese military officials refuse to acknowledge the size and scope of their space weapon and cyberwarfare programs, Chinese academics pump out an incessant stream of papers urging the PLA to develop techniques for “destroying, damaging, and interfering with” communications and reconnaissance satellites to “blind and deafen the enemy.” The list of potential Chinese enemies who could be blinded and deafened by a massive assault on satellites is rather short.

The Chinese government scoffed at the Pentagon’s findings and the latest U.S. defense appropriations bill, which angered Beijing by encouraging closer U.S. military cooperation with Taiwan. China’s Ministry of Defense accused the United States of retaining a “Cold War mentality” on Tuesday.