“A source who has spoken recently with top South Korean government advisers — and who spoke anonymously to preserve their confidences — told me Moon ‘freaked out’ last year when Trump was threatening ‘fire and fury’ against Kim.” We’re not sure whether Kim Jong Un was moved by Trump’s militaristic threats. But they definitely moved South Korean President Moon Jae-in. Axios: How a USB drive sparked the push for Korean peace.

+ CityLab: In Korean peace talks, all eyes are on denuclearization. But a plan to re-link the nations’ railways could be far more transformative.

+ “While there is no question Iran hid much of its weapons-designing past, North Korea has concealed programs on a far larger scale and built an arsenal of 20 to 60 nuclear warheads — compared with none in Iran.” From the NYT: Verifying the End of a Nuclear North Korea Could Make Iran Look Easy.