Economically there is nothing new about the Korean presence in Asean. Its companies were among the first to set up export factories in Vietnam more than a decade ago. Korean manufacturing investment is found everywhere in Asean. Koreans have bought up golf courses and colonized the tourist districts of Manila and Cebu in the Philippines. Their appliance manufacturers outsell all others in much of the region and Korean TV dramas have a huge following elsewhere in Asia.

The South Koreans are democratic at home but have made no effort to concern themselves with democracy or human rights elsewhere in Asia, a stance that appeals to many Asean members.

Until recently, Korea’s official presence was quite muted. Now it has both the confidence and money to make its own mark. Aid has been stepped up, and Koreans have been prominent in disaster relief efforts in Indonesia and the Philippines.

Seoul also has arms sales ambitions that could discomfort arms manufacturers from the United States, Europe and Russia, and before long China. South Korea is to supply Indonesia with submarines and is looking for arms business in Thailand, Malaysia and possibly Vietnam.

Some in Southeast Asia are wary of the hard-driving nature of Korean business, and worry particularly about its hunger for resources. Perceived Korean ruthlessness can upset easier-going Southeast Asians. But by and large Korea is very welcome — not big enough to be a threat but important enough to offer options to countries that have sometimes felt bullied either by the U.S., Japan or China.

The push for links with Vietnam may be especially significant given Hanoi’s key role in resisting China’s claims over the South China Sea, as well as the trade-dependent area’s interest in open sea lanes. So while neither China nor Japan will want to see South Korean influence expand at their expense, China probably has more to lose.