Kim Jong Un

The weekend saw an escalation in the war of words between Washington and Pyongyang, complete with a U.S. show of military might over the waters near North Korea and jitters over what seismologists say was an earthquake near a North Korean nuclear test site.

Updated at 2:45 p.m. ET

President Trump delivered a stern warning to North Korea's leader at the United Nations General Assembly Tuesday.

The blast was picked up by seismic stations all over the world, and it was big.

Updated at 4:00 p.m. ET Sunday:

North Korea claims it has again tested a hydrogen bomb underground and that it "successfully" loaded it onto the tip of an intercontinental ballistic missile, a claim that if true, crosses a "red line" drawn by South Korea's president last month.

In a state media announcement, North Korea confirmed the afternoon tremors in its northeast were indeed caused by the test of a nuclear device, and that leader Kim Jong Un personally signed off on the test.

Updated at 6:50 p.m. ET

"Military solutions are now fully in place, locked and loaded, should North Korea act unwisely," President Trump said on Friday, in his latest salvo in the exchange of rhetoric with the isolated regime.

Trump added, "Hopefully Kim Jong Un will find another path!"

Updated at 1 p.m. ET

As the leaders of two nuclear-armed countries trade threats, U.S. Secretary of State Rex Tillerson says President Trump "is sending a strong message to North Korea in language that Kim Jong Un would understand, because he doesn't seem to understand diplomatic language."

What makes North Korea feel so oppressive? If you ask its highest-ranking defector in decades, the answer is censorship. Thae Yong Ho, who was until last summer a Pyongyang envoy in London, argues that increasing the flow of information into the North is what can sow the seeds of popular discord to bring down the Kim Jong Un regime.