There are different countries that may initiate the start of World War III, but people are hoping that this is not going to happen. The weapons that countries may have right now are far more advanced as compared to the weapons that were used before. If a war is going to happen, it may wipe out all of humanity.
Some of the countries that may possibly start the World War are the following: The United States will probably want to start a war with different countries to show that this country is still one of the most powerful countries. Russia also has a chance of starting the war because of their current issues with international trade. Eve China may start the war to show that their power is constantly increasing.
Usually, spontaneous events or actions that could not be predicted start wars. So, it is difficult to determine which country is going to make the first move. Also, there are different countries that are at odds with other countries. Countries in the Middle East are angry with and have been angry with countries around the world. Also, North Korea is having problems with countries including China, Japan and United States.
Most likely, it seems that North Korea could begin World War III due to the pressure from other countries angering their leader. Commonly, North Korea presents its nuclear weapons in parades to prove that they have these weapons. To me, it means that they might be ready to start using them.