We often hear nothing about North Korea for
long periods, until there's a test related
to its nuclear program.
It's important to remember there are two kinds
of test.
One is a nuclear weapons test -- which is relatively
rare.
And the second is a missile test, which is
much more common.
But both are important because you need a 
reliable missile to deliver a nuclear weapon.
North Korea already has both and it's believed
to be working on upgrades.
It wants to make nuclear weapons that are
more powerful than the ones that it currently has.
And it wants a longer-range missile that could
potentially travel thousands of miles and
reach the United States.
North Korea thinks it needs a nuclear weapon
to protect itself, but the likelihood of
actually using it is considered very low -- not
zero -- but very low.
That's because using a nuclear weapon would
quite likely prompt action from other, stronger
countries that would then bring down the Kim
regime.
When we talk about North Korea we have to
consider three important outside actors.
Now, first is South Korea.
It believes the two Koreas will eventually
reunite someday.
But its approach has been very steady and patient,
and it's prepared to play the long game.
And No. 2 is China.
It's North Korea's only real ally and major
trading partner.
But even China has its limits.
It wants North Korea to behave responsibly
and predictably.
China's great fear is that North Korea could
collapse and that millions of North Korean
refugees could come streaming across the Chinese
border.
The third important player is the United States.
The U.S. has been deeply involved since it
fought alongside South Korea in the Korean
War of 1950-53.
But every time a new U.S. president comes
into office, it raises questions about whether
that policy might change.
So far, President Trump's rhetoric has been
more aggressive than his predecessors'.
And he sent an aircraft carrier off the Korean
coast.
This sort of classic gunboat diplomacy.
Most every U.S. president has had these moments
of high tension over North Korea but
for more than 60 years, it's always settled down
without the breakout of another war on the
Korean peninsula.
