North Korea on Wednesday launched two Rodong intermediate range ballistic missiles simultaneously. One exploded immediately after launch, while the other flew about 1,000 kilometers before landing inside Japan's exclusive economic zone (EEZ), making the first North Korean missile to make splashdown in Japan's EEZ.

This, together with two medium-range Rodong ballistic missiles and one shorter-range Scud missile on July 19, was a sign of North Korea's protest against the US and South Korean announcement they would jointly deploy the Terminal High-Altitude Area Defense (THAAD) system in South Korea. North Korea warned it would take "physical measures." Meanwhile, North Korea repeatedly stressed it will further develop nuclear deterrence and South Korean media reported that Pyongyang may conduct a fifth nuclear test soon.

As North Korea, China and Russia object to the THAAD system, if the US and South Korea insist on its deployment, it will be more difficult and complicated to realize denuclearization on the Korean Peninsula.

It is obvious that the deployment of THAAD provoked North Korea's further ambitions of nuclear and missile development, as illustrated by the launches of Rodong ballistic missiles.

Moreover, although the US and South Korea claimed that THAAD deployment is directed against North Korea's growing nuclear capability, China and Russia consider it as a threat to their own security because the radar system of THAAD can detect mass area in northeast China and far east Russia. Given the US rebalance to the Asia-Pacific, there is no way to convince China and Russia that THAAD is only directed against North Korea. Therefore, the determined opposition to THAAD by China and Russia may give North Korea the impression that divergences on denuclearization have emerged, especially among China, Russia, the US and South Korea. Pyongyang may also expect China and Russia to cancel their sanctions based on Resolution 2270 and even condone its further development of nuclear program.

Furthermore, it is inappropriate that the announcement of THAAD deployment came at a moment when international society should be evaluating the efficiency of Resolution 2270 after four-month execution.

It took a lot of effort for China to reach a consensus with the US and South Korea on putting stricter sanctions on North Korea, especially when bilateral relations between China and North Korea are going through a difficult time after Pyongyang's third nuclear test. China joined the US and South Korea and carried out Resolution 2270 seriously to try to press North Korea to change its attitude toward its nuclear program and also suggests all the parties talk to realize denuclearization, but in return the US and South Korea have stricken China a blow by announcing the THAAD deployment.

Finally, by announcing the THAAD deployment, the US and South Korea gave China and Russia good reasons to question their sincerity in solving North Korea's nuclear issue. It seems that the US and South Korea put a higher priority on defending themselves from Pyongyang's nuclear weapons than on solving the problem completely. It seems that the US and South Korea are admitting North Korea's nuclear development can't be reversed so that they need to defend against it instead of impeding it.

For China and Russia, THAAD deployment won't be of any help but will only make the situation more complicated and tense, and could even threaten the strategic balance in Northeast Asia, as well as China and Russia's security.

The decision on THAAD deployment has broken the consensus on pressing North Korea to change its attitude on the nuclear program. If no common view on THAAD deployment can be formed, and China, the US and South Korea cannot cooperate again, it will be more difficult to denuclearize the peninsula.

The worst consequence of THAAD deployment may not be whether it will damage China-South Korean relations or if China will loosen sanctions on North Korea, as South Korea worries about, but whether China, the US, and South Korea can keep working together on denuclearization.

The author is assistant professor at Shanghai Academy of Social Sciences. opinion@globaltimes.com.cn