FACED with repeated incursions of the maritime border with China in the Taiwan Strait, Taiwan is now facing its worst cross-strait military crisis in over two decades.
Tensions have escalated after China's People's Liberation Army sent dozens of warplanes into the island's air defence identification zone in the past month.
According to a South China Morning Post report, nearly 40 of those incursions involved warplanes crossing the median line of the Taiwan Strait.
The median line is the unofficial airspace boundary between Taiwan and China, and crossing that sensitive midline is a serious threat to the island nation.
"Once the PLA warplanes cross the centre line, it only takes 200 seconds to reach the nearest point on our coastline," said Wang Kung-yi, chairman of the Taiwan International Strategic Study Society think tank.
The northern Hsinchu city, lies just 36 nautical miles from the median line.
"And if our forces aren't decisive enough to intercept the intruders and stop them from reaching our territorial waters 12 nautical miles from the coast, it would only take another 80 seconds for the PLA warplanes to fly to Taipei," Wang said.
The recent incursions came as United States top officials Secretary of Health and Human Services Alex Azar and undersecretary of state Keith Krach visited Taiwan.
The Taiwan Strait median line was demarcated by US Air Force General Benjamin Davis Jnr in 1955, before the US pressured both sides to enter into a tacit agreement not to cross it.
Taiwan defence officials say the increased military activity and frequent crossing of the midline is comparable to the 1995-96 Taiwan Strait crisis, when the PLA fired missiles into waters around the island in a warning to then president Lee Teng-hui.
The SCMP report said 18 warplanes, including bombers and fighter jets, entered the southwest of the island's air defence identification zone from four directions on Sept 18 and at one stage, they were just 37 nautical miles off the Hsinchu coastline.
The next day, 19 Chinese warplanes including bombers, fighter jets and an anti-submarine aircraft again crossed the midline.
There are also reports that the PLA pilots responded over the radio that "there is no median line" when Taiwan's air force told them to leave.
Taiwan later held press briefings in a bid to draw international attention to the situation, saying the actions could lead to a cross-strait military conflict.
However, Beijing dismissed Taipei's claims, saying they were just normal exercises and that the median line never existed.
According to analysts, the incursions were meant as a psychological attack on the island, both its military and the public, and an effort to establish a norm that PLA warplanes can cross the median line whenever they like.
National Defence and Security Research Institute researcher Shu Hsia-huang said the median line crossings were about testing the reaction and attitude of Taiwan's air force.
But he did not believe the PLA manoeuvres, including its drills near the Taiwan Strait, were intended to provoke a military conflict.