The US Department of Commerce has reportedly sent a subpoena to Chinese telecom giant Huawei, demanding it to provide information concerning its exports to North Korea, Iran, Syria, Cuba and Sudan. The US has not accused Huawei of any wrongdoing, but if it finds the exports breached US regulations, the US may restrict channels through which Huawei can obtain US-made parts for high-tech products.

Similar investigations were also launched into Chinese tech company ZTE. The US announced in March that ZTE violated export controls on Iran, and punished the firm by barring high-tech components from its American suppliers.

Although the reasons behind the probes seemed noble, observers believe the US move is intended to blunt the competitiveness of Chinese high-tech firms.

While the two Chinese firms have kept a low profile in front of the US nit-picking, these incidents show the difficulty of global expansion for Chinese companies.

Although the US cannot take full control of the Chinese firms, it can raise the costs of their exploration of new markets by damaging their international reputation.

Huawei has entered markets around the globe, and has set up research institutes in India, Russia, Europe and the US, creating high-paying jobs and boosting local economic development. But the US still frames it within a geopolitical mind-set.

Huawei has been focusing on developing technology and is not good at politics. The irony is that it cannot escape political persecution.

The US is often known as the most open country in the world. Now what it is doing makes many people's jaws drop. Looking back, the Chinese government has been too friendly with US companies. US firms provided telecom equipment to China and sold their electronic products into the offices of government departments and research institutes. US firms were seen as cooperators instead of Trojan horses that might "jeopardize the national security of China."

It is time the Chinese government responds to the US side's freewheeling probes and sanctions on Chinese companies. The Chinese market is becoming increasingly important for US-based multinationals.

China's national security should be brought to the fore, and scrutiny over US firms in China should be enhanced.

It is necessary for China to complete related laws and regulations in order to better protect our national interests. If the US continues to use "national security" as an excuse for trade barriers, then US companies will have to pay a similar price. This will help the US government rethink their moves.