War with North Korea may only be a tweet away.

Imagine that you're a North Korean military commander. You have been taught from birth that the United States – which has thousands of troops just across the border – is an enemy just as intent on destroying your country today as it was when it was at war with your homeland 60 years ago. One day, you see a U.S. military plane outfitted to carry bombs approaching the borders of your country. You have a split-second to decide what to do, and you have orders to shoot if necessary. You recall persistent news coverage of the U.S. president's repeated statements in which he has threatened to annihilate you and your country.

What do you do about the plane?

You shoot it down.

The U.S. military then immediately responds by launching missile strikes against the weapons that shot down the U.S. plane. You have been told for years that this day will come – another war with the United States. You see the signs. They're sending planes. They're bombing you. It's time.

North Korea gives the order for artillery pieces to open fire on Seoul – home to 10 million people – and U.S. and South Korean positions along the demilitarized zone. It begins launching ballistic missiles against the South. And it gives the green light for its newly tested intercontinental ballistic missiles to launch against targets on Guam and the mainland United States. The United States responds in kind by launching an all-out assault with missiles on North Korea.

Hours later, millions have died. Much of North Korea, South Korea and certain U.S. cities are devastated. China begins moving its troops into North Korea to prevent a power vacuum. The U.S. and South Korean troops that avoided the devastation move north, trying to secure loose nuclear weapons. Chinese troops run into U.S. and South Korean troops in the North and don't know what to do because the countries have never truly planned for this contingency.

The chances of a war between the United States and China over the ashes of North Korea hinge on decisions made in those moments.

Hyperbole? Perhaps. But not as fantastical as one may think.

Incidents that could have sparked wider conflicts have happened before. In 1969, North Korea shot down a U.S. reconnaissance plane, killing the 31 Americans on board. In 1977, North Korea downed U.S. Army helicopter, resulting in three American deaths. In 1994, North Korea shot down another helicopter, killing one American. And these are a just a handful of the deadly incidents between America and North Korea over the years.

In these instances, U.S. restraint likely prevented a wider conflict, but fast forward to our current predicament. On Saturday, the U.S. military flew a B1 bomber plane right along the border with North Korea. Within hours of that flight, U.S. President Donald Trump took to Twitter and threatened that North Korea's foreign minister and leader Kim Jong Un "won't be around much longer!" Is it that hard to imagine that, in Pyongyang, officials and civilians see these acts and are preparing for the end times?

Kim Jong Un called Trump's threats in his United Nations speech "the most ferocious declaration of war in history." Days after Trump's tweet and the B1 flight, North Korean foreign minister Ri Yong Ho told the press that "since the United States declared war on our country we will have every right to make countermeasures," including "the right to shoot down United States strategic bombers even when they're not yet inside the airspace border of our country."

Today, conflict is still unlikely. Most North Korean rhetoric is just rhetoric. North Korea prioritizes regime survival, and so while it will continue to push the envelope with provocations, it is unlikely to attack first given the consequences for the regime.

While conflict is avoidable, brinkmanship now is different than in was in previous generations. North Korea has nuclear weapons. The restraint exercised by past U.S. presidents does not appear to be a virtue held by the current president. Growing talk about the ability of the United States to launch a preventive war or even a limited military strike against North Korea creates room for miscalculation, and miscalculation's stakes have never been higher.

The scariest talk is of a "limited" strike. The Trump administration has been sending signals indicating a willingness to use military force, including a strike it believes won't cascade into war. Secretary of Defense James Mattis has strongly hinted that a limited strike is one of his military options.

One can imagine this "limited" strike option being highly appealing to Trump. It would be an opportunity to show North Korea that the United States is willing to use military force, and like Trump's one-off strike against a Syrian airfield in April, Trump likely believes it would be a political winner.

The reality, however, is that there are no "limited" options. Even a single strike against North Korea runs irresponsible risks of an all out war.

But if Trump keeps tweeting, the United States may not even need to engage in a military strike on North Korea for a war to start. Miscalculation could start one anyway. It might just take a tweet.