President Donald Trump castigated Former President Barack Obama for drawing a line in the sand and allowing an enemy to cross it without a severe retaliation. President Obama was caught with the potential of starting World War III, so he chose to ignore the potential privation.
North Korean Leader Kim Jong-un realizing that Trump is a gambler decided to test his fortitude. Jong-un allowed the hurt of hurricanes Harvey and Irma to pass the USA thus reducing the glue that is holding the American people together. Therefore, Jong-un has sent a missile over Japan to rattle Trump’s nerves.
Jong-un needed to see if Trump would shoot down a NK Missile or find himself in a comparable position as Former President Barack Obama. Trump did not shoot the missile down over Japan, so he has emboldened Jong-un. My guess is China and Russia look forward to learning what new technology the US has to knock down missiles. It looks like Jong-un has won the war bluffing game.