SAKOKU, a new vocable from japanese ?

Where shall we be in one year ?

Still covid and no vaccine is a probable scenario.

“THE SPARED”, countries that were able to do the sacrifice of many social habits and protect the population, will be having a low covid diffusion rate and a high conscious level of self-accomplishment.
They will face “THE IMMUNIZED”, countries that had a large spread of the pandemic, killing many, and might consider, as having paid the price of a relative herd immunity, to be entitled to economical growth and travel freedom.

How will frontiers will open in this caricatural world ?

How will this affect the political relations and military balance for example of Japan and the US ?
More ever what would mean an isolation environment for a country in the 21st-century ?

Would SAKOKU (lock up of the country, isolationist foreign policy) become a new international vocable together with Kaizen, Kaiju, Emoji, Mottainai or Karaoke ?
Successful Japan’s 200 years long SAKOKU ended because the physical threat from outside was no longer matched by internal strength. Covid might lead us toward a long forgotten military escalation unless we find a “new normal” definition and application of SAKOKU.