High-power microwave weapons are useful for disabling electronics. They might also be behind the ailments suffered by US diplomats and CIA agents in Cuba and China.
The United States is the only developed, democratic country that has a political culture of selling ambassadorships.
Both sides can point to the Vienna Convention and to diplomatic tradition to support their case.
Data show that the US intervenes more in other countries' affairs than it did in the past. It also currently hires fewer career professionals for ambassadorial or foreign affairs positions.
Multiple sclerosis and endometriosis in women both used to be diagnosed as hysteria. The same could be happening with 'Havana syndrome.'
Kim Jong-un may be able to "chat" in English. That's not enough to understand Donald Trump.
Australia has joined its allies in expelling Russian diplomats as retaliation for a nerve-agent attack on a former Russian agent and his daughter. But the action is unlikely to trouble Russia.
Governments need to build trust, especially during a time of heightened tensions around the threat of international terror attacks.