China’s commercial aviation growth and transformation over the past 10 years has been astonishing.

With growth has come vast opportunity and commercial success for many of China’s airlines. In 2015, three mainland China carriers ranked in the top 10 of world airlines in terms of RPKs, passengers carried and fleet size; five placed in the top 20 in terms of net profitability.

Growth has also brought its challenges. Capacity and slot constraints are the biggest concern. China has 210 commercial airports, but just 27 of those airports handle about 65% of the average 23,500 daily take-off and landings and about 79% of passengers. In only five years, the Civil Aviation Administration of China (CAAC) estimates that demand for daily slots will increase to around 38,000.

Other concerns include an overly conservative aircraft separation policy. Combined with military training exercises that block out large chunks of airspace, this has led to inefficient traffic flows and chronic delays. There’s also a shortage of skilled professionals and technicians.

Beijing and CAAC are addressing those concerns. They have developed a five-year strategy plan that aims to triple capacity while also increasing safety (although China has maintained an excellent safety rate this past decade). They are creating four major aviation technical centers, optimizing some key routes, working with the military to free up more airspace, and identifying navigation and ATM technologies they can borrow from the US and Europe. These projects are beginning to pay off in reduced delays, but China knows much more must be done.

The harder challenge, however, will be to adjust China’s standing in the global air transport ecosystem so that it more correctly reflects the new size and importance of its airlines and market, passengers and cargo. Some 7 million passengers flew between China and the US last year; China’s middle class population is growing rapidly and it’s a demographic that will travel and shop.

US policy, however, seems to be skirting the opportunity. Instead of real movement toward a more liberalized aviation agreement with China, there is talk about the need for “more transparency and fairness” in how Beijing allocates its slots. Chinese carriers, meanwhile, are fast hitting the ceiling of US routes they are permitted to serve.

The slot talk is misleading; China’s capacity constraints are not new. They can be addressed, through the efforts being implemented by CAAC or through creative “slot swaps” between US and Chinese carriers.

What seems to be more at play here is a new-found American reticence toward liberalization. That’s regrettable and a grave mistake. The huge and fast-growing Chinese market is an opportunity not just for Chinese carriers but for all those who embrace it. If the US does not seize the moment and truly make China its aviation partner, others will.