BEIJING -- The Chinese People's Liberation Army (PLA) Eastern Theater Command on Monday started joint drills involving its Army, Navy, Air Force, and Rocket Force troops in five areas surrounding Taiwan Island.

Codenamed "Justice Mission 2025," the drills were conducted in the Taiwan Strait and waters to the north, southwest, southeast, and east of the island, to combat "Taiwan independence" separatist activities and external interference.

Military experts summarized three key takeaways of the drills.

WHY NOW?

Wang Wenjuan, a researcher with the Academy of Military Science, said the drills were launched against the backdrop of increasingly frequent collusion between the United States and Taiwan's Democratic Progressive Party authorities.

She noted that Taiwan leader Lai Ching-te has claimed he would push for an "unprecedented" arms procurement worth $40 billion, while the United States has announced a new round of arms sales to Taiwan totaling more than $11 billion?-- far exceeding previous packages.

Such actions, Wang said, seriously violate the one-China principle and the three China-US joint communiqués, particularly the August 17 Communiqué.

"Taiwan is at the core of China's core interests and represents the first red line that must not be crossed in China-US relations," said Fu Zhengnan, also a researcher with the Academy of Military Science. He stressed that the drills are precisely targeted at resolutely punishing separatist forces and deterring external interference.

Li Jian, a researcher with the Naval Research Academy, said the drills are a necessary move to safeguard peace and stability across the Taiwan Strait and to advance the process of national reunification.

"The PLA conducting military operations within China's territory, airspace and territorial waters is indisputably legitimate and lawful," Li said.

WHAT DISTINGUISHES THE LATEST DRILLS?

According to the spokesperson of the Eastern Theater Command, the drills focused on such subjects as sea-air combat readiness patrol, joint seizure of comprehensive superiority, blockade on key ports and areas, as well as all-dimensional deterrence outside the island chain.

With vessels and aircraft approaching Taiwan Island in proximity from different directions, troops of multiple services engage in joint assaults to test their joint operations capabilities, the spokesperson said.

Based on a comprehensive assessment of the situation, experts said the exercise demonstrated three prominent features.

Zhang Chi, a professor at the National Defense University, said the first notable feature was that "action began immediately at the outset." As soon as the exercise started, participating forces conducted live-fire naval gun drills.

He noted that this demonstrates the PLA's ability to integrate peacetime training with wartime operations and sends a strong signal of its resolve to crush all separatist plots resolutely.

On Tuesday, the Eastern Theater Command carried out long-range live fire drills.

"This use of firepower combines long- and short-range strikes as well as high- and low-altitude capabilities," Zhang said. "All energy facilities, major ports and military bases relied upon by 'Taiwan independence' separatist forces fall within the PLA's firepower coverage, fully demonstrating the PLA's powerful deterrence and joint strike capabilities against Taiwan Island and its surrounding areas."

Li said the second feature lies in the formation of a posture described as "encircling on three sides while leaving one direction open."

"This sends a clear message that seeking 'Taiwan independence' through external support is a dead end, while returning to the motherland is the only viable path," Li said.

Zhang added that the three-sided encirclement demonstrates the PLA's capabilities of pressing and containing separatist forces while denying access to external interference -- an approach summarized as "sealing internally and blocking externally."

The third feature, Zhang said, is that the encirclement around the island is tightening further.

"The PLA has fully exercised its capabilities to seize air and sea control over key areas and conduct long-range, precise strikes against important targets," he said.

WHAT MESSAGE THE DRILLS SENT?

Taiwan is an inalienable part of China's territory, and China will never tolerate any attempt by "Taiwan independence" separatist forces to collude with external forces in seeking secession.

The PLA will never hesitate in striking against "Taiwan independence" and promoting reunification. It will continue to conduct operations countering separatism and foreign interference, resolutely safeguarding China's sovereignty, unity, and territorial integrity, said Zhang Xiaogang, spokesperson of China's Ministry of National Defense.

Zhang Chi said the PLA has always been willing to make the greatest efforts to preserve peace, but its resolve to safeguard national reunification remains unshakable.

"The people's army is ready to fight and fight to win," he said.

Fu noted that many Chinese believe that only by being fully prepared for combat can war be effectively prevented.

He said the PLA's equipment system is undergoing rapid iterative development toward informatization and intelligentization, particularly in strategic deterrence forces, which now feature integrated all-domain capabilities and global reach.

"The growing strength of the PLA is a strong guarantee of peace and stability across the Taiwan Strait and of the security and well-being of compatriots in Taiwan," Fu said.