The United States on Thursday announced it had approved the sale of equipment and technology of Patriot air defense missiles to Taiwan for $620 million. This is the second arms sale to the island this year and the seventh since Donald Trump became president.

The US has for years sought to use Taiwan as a means to contain China and maintain its strategic presence in the region. Previous administrations have also made weapons deals with the island, but their increasing frequency since Trump took office shows that the island has greater prominence in US strategy. Not only are the deals lucrative for the US arms manufacturers but they also embolden the pro-independence administration on the island in its troublemaking, which serves Washington's strategy of trying to keep Beijing busy putting out fires.

However, Tsai Ing-wen should not misjudge the situation in the Taiwan Straits and underestimate Beijing's resolve and capability to safeguard its sovereignty and territorial integrity. To do so would be a costly miscalculation.

If the Chinese mainland decides to reunify with the island by force, Taiwan will simply become another abandoned chess piece of the US. For Washington, the value of the island lies in how much it can be used to apply pressure on Beijing.

It is hard to believe the US seeks a head-on military confrontation with the Chinese mainland over Taiwan, as such a scenario will lead to unfathomable consequences. It cannot possibly serve the US interests. So it is stupid for the pro-independence forces on the island to get elated by the US arms sales as the US is not prepared to make any sacrifices for Taiwan.

Instead of intimidating Beijing, Washington's intensified provocations, whether by sending military aircraft and warships near the island more frequently or playing the arms sales card more often, has simply reminded it of the importance and urgency for accelerating the modernization of the People's Liberation Army.

The US arms sales to Taiwan do not change the fundamental cross-Straits balance of power. The Taiwan authorities acknowledged in 2015 that the mainland had the ability to stop foreign forces from intervening in the Taiwan Straits. So the US' so-called security commitment to the island is an empty promise. Washington knows this of course, but it is quite happy to keep the US Navy sailing near the island if it means it can make some money clearing out its military cupboards.