With the world's six year olds staring at each other in a game of global brinkmanship; where they can both engage in the equivalent of throwing very big bricks at each other; where they both have the capability of crying 'havoc' and letting slip the dogs of war, I thought it would be interesting to sort out why and how we got here.
Once upon a time, Korea, as in one single Korea, was ruled by Heungseon Daewongun. His government was overthrown by the Empress Myeongseong "Queen Min" and in the ensuing period of instability, Japan deployed literal gunboat diplomacy by deploying the gunboat Unyo. The Japan–Korea Treaty of 1876 was signed by representatives of Emperor Meiji and Emperor Gojong and eventually in 1910, Korea fell to being a complete puppet state of Japan.
Japan had designs of being an even greater empire and this worked out reasonably well for them, provided you completely disregard their effects on Korea, China, Thailand, Burma, Indonesia, The Philippines, Papua New Guinea... which all came to a sudden and abrupt halt in 1945 following four years of conflict with the United States and the dropping of two extinction balls.
Most of the affected nations of South East Asia went on to have complex and strange stories but China decided to have a civil war and then a communist revolution, but Korea was kind of in a weird place.
By applying the same sort of insane logic which didn't work in eastern Europe, the USSR and the United States drew a line in Korea along the 38th parallel, with the USSR in control of the north and the United States kind of administering the south. Neither side accepted the line as permanent and on the 25th of June 1950, forces from USSR backed north decided to cross the line and for 3 years a sort of war broke out out between the Communist back forces of the north and a United Nations supported force in the south which mostly consisted of the United States.
The war which was called a war by everyone except the United States government, ended in 1953 having achieved pushing the Communist back forces of the north back across the line and not much else. There is a demilitarised zone between the two forces (neither of them regard each other as legitimate) but 64 years later, a state of war nominally exists except for the United States where a state of war never actually started.
The Congress shall have power to...
To declare war, grant letters of marque and reprisal, and make rules concerning captures on land and water;
- Article I, Section 8, Clause 11, US Constitution, 4th Mar 1789
According to the US Constitution, it is the Congress who has the power to declare war and not the President. Because of this there has always been a legal question about whether or not President Harry S Truman ever had the authority to engage the forces of the United States in a war without congressional approval.
The President shall be commander in chief of the Army and Navy of the United States, and of the militia of the several states, when called into the actual service of the United States;
- Article I, Section 2, Clause 1, US Constitution, 4th Mar 1789
Article I, Section 2, Clause 1, US Constitution, vests the office of the commander in chief of the Army and Navy in the person of the President but to what extent the President has authority to use the military, when they don't have the approval of the congress, was mostly untested and unknown in 1950. Mostly because the Constitution is silent on the issue, opinions vary widely on what authority the President has. This was tempered with the War Powers Resolution of 1973, which gives the President the ability use force for 60 days without approval and then requires that that force be removed within 30 days; the most recent obvious example of this being used was by President Obama; following the 2012 Benghazi attack by the Islamic militant group Ansar al-Sharia.
In 1950 though, this Act did not exist and given that this was set against the backdrop of the Cold War, nobody really thought to challenge the legality of the operation.
In 2017, North Korea has finally found that it can threaten the United States and with Donald Trump as the commander in chief; who under the War Powers Resolution of 1973, can use military force for up to 60 days without congressional approval, this is where we find ourselves today.
Considering that North Korea has a string of artillery pieces very close to the 38th parallel, they could rain down a show of firepower in very very quick time indeed. If an exchange of artillery fire were to happen, then even the crappiest of missiles would be able to hit downtown Seoul in even less time than it would take for the President to react. If deployed, a North Korean Rodong-1 missile would take roughly 33 seconds to hit Seoul.
I don't think it particularly wise to let six year old children start throwing bricks at each other. I don't see anything different in principle between two six year old children and Kim Jong-un and Donald Trump, except that the bricks are far far larger. What is legal and what is sensible, are vastly different.