Republican leaders scoffed at that assessment and suggested that Pyongyang’s belligerence is part of a pattern of behavior from rogue states during the Obama presidency. House Speaker Paul D. Ryan (R-Wis.) cited Obama’s decision not to enforce a ­self-proclaimed “red line” after Syria used chemical weapons in 2013 and said the North Korean nuclear test “is exactly what happens when we appease and embolden rogue regimes.”

Ryan added that the situation on the Korean Peninsula, where the North violated a nuclear deal during Bill Clinton’s administration, should cast doubt on the sanctity of Obama’s Iran deal.

The difference between the level of U.S. engagement with Iran and with North Korea led some Asia analysts to conclude that the administration had downgraded the latter country as a national security priority…

“China does not seem to have been trying very hard on North Korea,” said Cha, now an analyst at the Center for Strategic and International Studies. “This is China’s responsibility, but the administration could have done more to make this a higher priority. When the president sits down with the Chinese president, there’s a list of things they want to talk about. My guess is North Korea is fifth or sixth on the list. During the Bush administration, it was the top issue on the list.”