The Republic of China Army (ROCA) has commissioned 15 more Boeing AH-64E Apache Guardian attack helicopters, bringing to 29 the total number of these tank killers it can bring to bear against any invasion launched against the Republic of China (Taiwan) by mainland China.

Taiwan made a big show of the commissioning of these 15 Apaches earlier this week. Taiwan president Tsai Ing-wen described the event as a milestone in Taiwan's defense against a mainland invasion. She also said the acquisition of the Apache Guardians was part of Taiwan's multiple deterrence strategies to counter a mainland invasion. Many Taiwanese and the Taiwan government expect a mainland invasion to occur by 2020.

Tsai emphasized that the two Apache squadrons will "play a pivotal role in boosting Taiwan's combat capabilities and its defensive needs." She also pledged that her "government will make sure to fully support the military to follow up and further enhance the helicopters' capability."

The United States sent military officers to observe the commissioning of the attack helicopters.

All 29 Apaches are based at the Longtan Air Base in Taoyuan, in northern Taiwan, said the Ministry of National Defense. The decision to deploy the Apaches to the north of the island is strategic: it will allow the Apaches to attack and destroy invading units of the People's Liberation Army Ground Force that might make inroads into Taiwan from the north coast.

Taiwan brought 30 AH-64Es from the United States for $1.96 billion in 2008. The helicopters were all delivered by October 2014 but one crashed during a training flight.

The 29 Apache helicopters, which will outfit two squadrons, will be operated by ROCA's 601st Air Cavalry Brigade. The brigade is part of the Army Aviation and Special Forces Command (AASFC) based in Taoyuan's Longtan District. The first Apache squadron was commissioned in July 2017 with the second reaching operational readiness earlier this year.

ROCA's AH-64Es are armed with a 30 mm M230 Chain Gun and can be armed with AGM-114 Hellfire air-to-surface missiles; Hydra-70 2.75-inch rocket pods and AIM-92 Stinger air-to-air missiles. The AH-64E is currently the most advanced version of the Apache in operational use with the U.S. Army.

The ROCA Apaches are also equipped with the AN/APG-78 Longbow fire-control target acquisition radar, which gives the helicopter day/night, all-weather, 360-degree search capabilities for both air and ground targets up to a range of 8 km. The AN/APG-78 can track 128 targets simultaneously and its 16 Hellfire missiles can be deployed in less than 30 seconds.