・launch a missile ＝ ミサイルを発射する
・possess nuclear weapons ＝ 核兵器を保有している
・economic sanctions ＝ 経済制裁
・take economic sanctions against～ ＝ ～に経済制裁の措置をとる
・retaliate against～ ＝ ～に仕返しする、報復する
・take a retaliatory step against～＝ ～に報復する
・preemptive attack ＝ 先制攻撃
・carry out preemptive attack ＝ 先制攻撃を行う
・treaty ＝ 条約
・promote dialogue ＝ 対話を促す
・catastrophic ＝ 大惨事の、悲劇的な
・provocative ＝ 挑発的な、刺激の強い（えろい）←※日常会話でよく使われます
Q1．Are economic sanctions against Noth Korea effective?
I don't suppose sanctions of any kind are effective. The leader of NK and his surroundings will occupy the large part of the money in the county. It's only their citizens that will be affected by the sanctions imposed. Even if there were tougher sanctions the NK would continue to experiment new missiles. In the worst case, they might start a war, which will result in a catastrophe.
Q2．Why does NK stick to the experiments on nuclear weapons?
The US possesses strong nuclear weapons and is a threat to NK, and NK is desperate for the position as a nuclear weapons possessing county in order to compete with the US. It also wants to control diplomacy by showing off its power to the rest of the world.
Q3．What can other countries do to prevent the war?
I don't think any country has found a solution yet. Some countries such as China and Russia insist that economic sanctions won't work and that what they should do is promote dialogue.
Is the war between the US and NK likely to happen in the near future?
Today the relationship between the United States and North Korea has been tense. Some people argue that the war that involves nuclear weapons is to break out very soon. I agree with them for the following reasons.
Firstly, the US is a great threat to North Korea and vice versa. In spite of the warning from the US, NK is keeping the experiments on nuclear missiles. Obviously this is against non-nuclear weapon treaty and provocative enough to make America carry out preemptive attack for self defence.
Secondly, NK wants to show off its power by the use of strong nuclear weapons in the war. North Korea is not blessed with natural resources. Of course it cannot get oil itself. This means there is no choice but to depend on other countries for them. NK intends to threat other nations so it can control the supply of oil and other resources in a way it wants. The war can be a good opportunity to do so.
Thirdly, the leader of North Korea is very cruel and insane. He doesn't feel anything about getting rid of things that can bother him, even if they are people. He will take any measure in order to achieve his objectives.
For these three reasons, I think that the war between the two countries is likely to happen in the near future. (227 words)
Today we can hear a lot of news about the conflict between the United States and North Korea. Although some people argue the war between the two countries is likely to happen, I don't think it will break out in the near future for the following three reasons.
Firstly, the leader of both countries are smart enough to understand the great impact that a war involving nuclear weapons can have on earth. If the two countries that possess strong nuclear weapons started the war, it would destroy the most parts of the world. Neither NK nor the US wants it.
Secondly, North Korea is just showing off its power as a nation with nuclear weapons. North Korea is not blessed with natural resources as well as oil. As NK has to depend on other nations for the resources, it intends to threat them so it can control the supply of oil and other resources. It doesn't really want a war.
Thirdly, although the leader of NK is said to be insane as he never gives up experiments on nuclear missiles, he is obviously afraid of a number of great weapons that the US possesses. If NK attacked the US, it would take a retaliatory step with more powerful nuclear weapons. NK is also afraid that most of the developed countries will turn out to be its enemies if it starts the war.
In summary, both the US and NK understand that the nuclear war just results in catastrophe. In terms of NK, especially, it just intends to use its weapons as the way of diplomacy and doesn't want to make enemies by starting the war. This is why I believe the war will not break out. (over 250 words)