Chiu Kuo-cheng, Taipei’s defense chief, told local lawmakers that a serious airspace incursion, and not just a missile strike, could warrant a counterattack by Taiwan’s armed forces.

He told the island’s Foreign and National Defense Committee that the previous definition of a “first strike” by Beijing would be expanded to accommodate harassment of Taiwanese territory by Chinese drones as well as the Chinese military moves closer and closer to Taiwan’s shores.

Lo Chih-cheng, a lawmaker with Taiwan’s ruling Democratic Progressive Party, sought to clarify whether a Chinese aircraft entering the island’s territorial airspace could be considered a “first strike.” Chiu replied: “Yes, that’s correct.”

“Of course, we have a red line. We absolutely will respond,” he said.

Tensions in the Taiwan Strait spiked to the highest level in decades in early August after Beijing launched a series of war games in response to a visit to Taipei by House Speaker Nancy Pelosi. The unprecedented moves included the launching of 11 ballistic missiles, some of which flew over the island before landing in the Western Pacific.

More concerning for defense planners, however, was a marked escalation of China’s warship and warplane patrols in Taiwan’s surrounding sea and airspace. Chinese military aircraft have also ventured past the Taiwan Strait “median line” on a near-daily basis.

Having done so fewer than two dozen times in 2020 and zero times in 2021, Chinese fighter aircraft and military drones have crossed the unofficial territorial line more than 400 times this year, all but one of the instances happening after early August, according to an open-source database compiled by U.S.-based analysts Gerald Brown and Ben Lewis.

The median line was drawn up by the United States in the 1950s as a way to rein in Cold War hostilities between Communist leaders in Beijing and the remaining Nationalist government in Taipei. Its existence, although unofficial, was largely respected for seven decades.

With the balance of power now overwhelming in its favor, Beijing appears confident enough to ignore the center line separating both sides of the strait, which is about 80 miles wide at its narrowest point.

Wu Qian, China’s defense ministry spokesperson, told a monthly press conference in late July: “Taiwan is part of China. There is no so-called median line between both sides of the Taiwan Strait.”

Taipei rejects Beijing’s claim, insisting that Taiwan’s fate be decided only by its 23.5 million residents

“The median line was supposed to be a tacit agreement for everyone,” Chiu told legislators on the defense committee. “That tacit agreement has been destroyed.”

Chiu said Beijing had created “a new normal” with its military activities further in the Taiwan Strait, and it would be a challenge to return to the status quo. “But we will stand firm when they come. We haven’t changed.”

The defense official said Taiwan’s forces would continue to operate in patrol and training zones east of the median line.

Hung Tzu-chieh, a researcher with the Institute for National Defense and Security Research, Taiwan’s top military think tank, said the risks associated with a new normal were twofold.

“First, it risks an accident between the People’s Liberation Army and Taiwan’s armed forces,” he told Newsweek. “Secondly, China could use another political incident as a pretext to move its military activity even closer to Taiwan, creating another new normal.”

“Militarily, if the PLA were to ambush Taiwanese troops in the future, it could give Taiwan’s forces less time to react,” Hung said.

“I believe the defense ministry’s current response is correct. Taiwan won’t provoke but has drawn a red line,” he said.

Also Wednesday, Taiwan’s Premier Su Tseng-chang presented the cabinet’s budget for the fiscal year 2023, including a 12.9 percent hike in defense spending, the first double-digit rise in recent years.

The island’s military expenditure, after accounting for additional special provisions, was slated to reach $18.57 billion next year.