An electron source is a bond or a lone pair of electrons. It is either a p bond or a lone pair on an atom of relatively high electron density in a molecule or ion, or a bond that must break during a reaction. An electron sink is an atom on a molecule or ion that can accept a new bond or lone pair of electrons.
What Military Threat Does North Korea Pose? It is impossible to say whether the recent threats from North Korea constitute a clear and immediate danger or whether the strong threats are just bluster in order to extract food aid and technical assistance from the international community.
It poses no existential threat to the US. But it does pose a minor existential threat to the US's close allies (South Korea, Japan and to a lesser extent, the Philippines). It poses a far greater security threat whereby it hacks American businesses, counterfeits US dollars and markets weapons to organizations that the US (nor its allies) want those weapons going to.