The High Mobility Artillery Rocket System (HIMARS), which has been listed on a large-scale arms sale package from the United States to Taiwan, is like a "porcupine trapped in a one-way glass box" due to its visibility and limited mobility, a Chinese military expert has said.

Fu Zhengnan, a researcher at the People's Liberation Army's Academy of Military Science, said Taiwan's geographical conditions severely constrain the HIMARS "shoot-and-scoot capability". The rocket systems are part of the US $11.1 billion arms sale to Taiwan announced on Dec 17.

The defining feature of HIMARS is high mobility, designed for wide and open terrain, such as flat plains and deserts, where its operational strengths can be fully utilized, according to Fu.

"Although it has spikes, it cannot run, hide or maneuver freely on the island," Fu said, noting that Taiwan's narrow, mountainous landscape and dense population sharply limit the rocket system's operational space.

Fu added that while HIMARS is fully visible from the outside, Taiwan's forces inside are unable to detect incoming threats in time, making the rocket system more exposed and easier to target.

"It is harder to survive in a high-intensity conflict," he said.

"Its high mobility becomes theoretical under such circumstances."

In contrast, Fu said the People's Liberation Army's long-range rocket artillery, which also consists of launchers and ammunition, can operate from greater coastal depth with longer range, higher firepower and sustained strike capability.