We've all read the headlines about the threat of nuclear war from North Korea or another country.

It seems like a problem out of a sci-fi book, but there are real and practical applications to the scary proposition.

The question is: Is America ready for the possibility of nuclear war?

President Donald Trump is headed to Asia this week, and the conflict with North Korea will be on many people's minds.

So far, it's just a war of words between Trump and North Korea's Kim Jong-un.

But what if the war of words escalated into the unthinkable: A nuclear war?

"We are not looking to the total annihilation of a country, namely North Korea. But as I said, we have many options to do so," said U.S. Defense Secretary James Mattis.

The American nuclear arsenal is fearsome, though not as overwhelming as it once was.

Fifty years ago, at the height of the cold war, the United States had 30,000 nuclear warheads. Today, all the world's nuclear-armed nations possess half that many warheads -- about 15,000. Nine of every 10 warheads belong to the United States or Russia.

Russia has a slight edge in nuclear weapons.

The country has deployed 1,561 warheads on ballistic missiles or at military bases The United States has deployed 1,393, while North Korea is believed to have the material for a maximum of 20 warheads in three years.

An American strike on Pyongyang would leave 1.6 million people dead and injured. A North Korean strike on Los Angeles would kill or injure 900,000, while a strike on Phoenix would kill 82,000 and injure 217,000, according to NukeMap.

We've verified America has the nuclear capability to respond to an attack with devastating force.