Detection of an earthquake in the northeastern part of North Korea quickly led to speculation that the country had conducted its fourth test of a nuclear device. A subsequent announcement from the regime that it would make a statement late Tuesday evening seems to have left little doubt.

Even without that announcement, though, the evidence seems pretty clear. The location and magnitude of the temblor closely matched North Korea's three past nuclear tests. The U.S. Geological Survey has detected only one other quake of magnitude 4.0 or above in North Korea since 1990 -- far from the region where the tests and this latest quake were clustered.

This is akin to walking into the scene of a murder at an English country estate and finding the butler's fingerprints all over the place and a bloody knife in his coat pocket. Maybe it's not what it looks like, but it's probably what it looks like.

A 2016 which already looked as though it would be focused on foreign policy, between the rise of the Islamic State and the pending deal with Iran, likely just got another old favorite to work into the mix.

Update: The butler did it.