This is a biowar hypothesis to explain several anomalies in this pandemic.   There are two CoronaVirus (CV)  strains: "S", which is low fatality and "L", which is high fatality.  Let's see how these two strains might interact in a biowar strategy to explain the current statistics.

Suppose the S strain is released into the United States in mid-2019.  This explains the deaths being attributed posthumously to CV.  The benign strain spreads for several months, killing a few people (although more than the flu) but also imbuing CV immunity to millions.

The S strains spreads across the US, setting a foundation for "herd immunity".  This also explains the numerous Americans who believe they'd already had the CV flu in late 2019 as well as the lack of testing by Trump administration/CDC.  Exhaustive testing would expose the extent of the S strain immunity.

The L strain is injected into Wuhan, China, knowing it will take a couple of months to spread beyond China.

Both infections spread from their respective starting points.  The S strain mostly immunizes Americans, the L strain mostly kills Asians at an enormous rate.

Eventually, the L strain reaches Iran and kills many, then continues towards Europe (and Italy).  It reaches South Korea but due to the large presence of US servicemen, the S strain already has a foothold and reduces L strain casualties.

When L strain reaches the United States, the S strain has almost finished herd immunity.  The L strain kills some but then fades out in late April because it can't get traction in an immunized population.  It continues killing large numbers outside of the United States.

We can look for future validations of this theory:

1) CV "mysteriously" fades out in the United States in April/May.

2) CV continues killing large numbers outside the US.

3) The ratio of deaths is roughly equivalent to distance from US (or accessibility).  Less exposure to US carriers equals higher deaths, percentage-wise.