Japan didn't wait for a UN lead before imposing its own sanctions Wednesday on North Korea.
The swift move is a sign of the more assertive stance that Prime Minister leader Shinzo Abe wants to adopt toward Pyongyang, but is also seen as part of a broader tactic to create a united front under US leadership among countries in the region.
"The full involvement of the US is indispensable," says Akihiko Tanaka, a professor at Tokyo University. "In addition to an active stance from Japan, it is essential that South Korea and China show a much more cooperative attitude with the US."
Mr. Abe has tried to build consensus since North Korea's test. In Seoul Monday, he said that his views and those of South Korea were in accord as "the security dynamics in Northeast Asia enter a new phase."
Abe rose to prominence by taking a hard line on issues such as North Korea's abduction of Japanese citizens in the 1970s and '80s. The threat from the North has boosted his popularity. But Asian neighbors are wary of his views on World War II and his ambitions for Tokyo to play a diplomatic role commensurate with its economic clout.
Speculation has surfaced that Japan may seek nuclear capability. A 2003 poll showed that almost 1 in 5 lawmakers think Japan should consider going nuclear if warranted. Abe has said in the past that Japan has the right to nuclear arms. But Tuesday he said, "We absolutely do not have the option of owning nuclear weapons."
Tokyo's sanctions should be considered mainly symbolic, say analysts. Tokyo imposed a six-month ban on North Korean imports and exports. North Koreans are barred from Japan, as are North Korean registered ships.
Because trade is light, "the effect is likely to be quite limited," says Tatsushi Shikano, of Mitsubishi UFJ Research and Consulting. Exports from Japan to North Korea in 2005 totaled 6.5 billion yen ($58 million). Imports were valued at 14.5 billion yen ($121 million).