The North Korea -US summit kicked off Wednesday night in Hanoi, Vietnam, garnering the attention of the world. There is symbolic significance to have this meeting convened in Hanoi. Despite being a staunch foe of the US in the past, Vietnam now has the best relations with the US among all socialist countries. "Vietnam is thriving like few places on earth. North Korea would be the same, and very quickly, if it would denuclearize," US President Donald Trump tweeted ahead of the meeting. The change of Vietnam from US enemy to friend is appealing to North Korea.For socialist countries to advance reform and opening-up, they must develop relations with the West, especially the US. Like Vietnam, if North Korea wants to develop its economy, it must first improve relations with the US. North Korea's neighboring countries, such as China and South Korea, all support North Korea taking the step.Because of Vietnam's geopolitical significance, the US treats Vietnam better than other socialist countries. Vietnam is one of the major countries in Southeast Asia and has territorial disputes with China. Strengthening relations with Vietnam could bolster the US policy toward China. But Vietnam is a socialist country. It won't relax vigilance against US political subversion. No matter how close Vietnam-US relations, it will never become a US ally like Singapore or South Korea.North Korea intends to improve its relationship with the US. However, North Korea's domestic politics has a more serious conflict with the US system and its geopolitical environment is quite different from that of Vietnam.Among Northeast Asian countries, North Korea has the smallest population. Its improvement of relations with the US faces a complicated influence from the US-South Korea alliance. The two Koreas are of the same ethnic group and it is an aspiration of South Korea to lead the unification of the Korean Peninsula In other words, the best relationship that North Korea and the US could have is one like the US-Vietnam relationship. But constrained by the factors mentioned above, it's difficult for the US and North Korea to make their relations reach the level of that between the US and Vietnam.Despite territorial disputes, China is Vietnam's largest trading partner. The party-to-party relationship has played a special role in bilateral ties and is of great significance in maintaining Vietnam's long-term stability. It also has served as the biggest external driving force for Vietnam's economic development.Vietnam won't develop its relations with the US at the cost of that with China. It's in Vietnam's best interests to develop relations simultaneously with both countries. China's other neighboring countries will also make such a choice.It's assumed by some that an improved US-North Korea relationship will eventually undermine the China-North Korea relationship and advancing denuclearization process means more uncertainties in China-North Korea relations. Such views were particularly popular in 2017 and the beginning of 2018.The China-North Korea summit in 2018 was held before North Korean leader Kim Jong-un 's meetings with South Korean President Moon Jae-in and Trump. The rapidly restored China-North Korea ties made that speculation fade. But it hasn't vanished. Some Americans suspected that Beijing want to undermine the negotiation process between Washington and Pyongyang. Such a suspicion was based on the same mistaken idea that China harbors jealousy toward any improvement in US-North Korea ties.