"The fourth level": America is studying an exceptional decision to confront Corona

With the widespread outbreak of the Coronavirus, the administration of President Donald Trump is considering upgrading its already existing warning to Americans against international travel.

US officials said on Thursday that the State Department may soon issue a new warning urging Americans not to travel abroad, under any circumstances.
The officials spoke on condition of anonymity because no final decision had been taken and the warning could be eased, even if it was approved, according to what the Associated Press reported.
Currently, the department advises US citizens to "reconsider" all international flights in light of what is known as a "third level" alert.
The issuance of a "fourth level" global warning would be unprecedented, because such warnings are generally limited to specific countries experiencing conflicts or natural disasters, or where Americans face specific risks.

However, even if the upgrade from "level 3" to "level 4" is approved, this will not have much practical impact as it is not mandatory, and there are now limited transportation options for international travel.
The only way to prevent Americans from traveling abroad is to revoke the use of American passports for such travel, a condition that currently exists for North Korea only.
In addition, the main effect of travel warnings at the State Department is to have insurance companies increase insurance premiums or cancel travel policies for the group and individual trips, many of which were canceled even before the warning was raised to the third level earlier this week.