WWIII

You really only see this in extremely developed countries which are few of the many. Japan is the most famous example for being in the 4th stage of its demographic transition due to low birth rates and immigration. Low birth rates are indeed related to education, but it's primarily dictated by women. As a rule of thumb, the less economically developed the country is, the lower stage they tend to be. USA's population (pictured below), for example, is currently in 3rd stage. What I find interesting about it is how the Baby boomers are very defined in the top middle of the pyramid right before declining into the Silent Generation. 

china with an islamic country would initiate third world war

I think it will be mongolian civilization with semites against INDO-EUROPEANS.

I think if WWIII does start, China and or Russia will be involved in some way.

I think it will happen at some point, I believe it will be over rather quickly, especially in the age of nuclear weapons.

There is a lot of space on Earth, the cities are overcrowded, but the the planet itself. 

Look at Macau. The population density there is 21 224 of people per square kilometer. The population density on Earth is 49 people per square kilometer, counting only lands, not water areas. To make the whole world have same population density as Macau, there would have to be 443 times more people right now. In 2015 there were  7 200 000 000 of people on Earth. Now multiply this by 443. 

Regarding the question itself, I doubt if there will be a World War III, no one wants to start it and there are less lethal methods to piss somebody off. But something tells me that a whole bunch of conflicts is ahead.

From an alleged letter from a guyhih in the Masonic order Albert pike to another dood named mazzini.

he Third World War must be fomented by taking advantage of the differences caused by the 'agentur' of the 'Illuminati' between the political Zionists and the leaders of Islamic World. The war must be conducted in such a way that Islam (the Moslem Arabic World) and political Zionism (the State of Israel) mutually destroy each other. Meanwhile the other nations, once more divided on this issue will be constrained to fight to the point of complete physical, moral, spiritual and economical exhaustion…We shall unleash the Nihilists and the atheists, and we shall provoke a formidable social cataclysm which in all its horror will show clearly to the nations the effect of absolute atheism, origin of savagery and of the most bloody turmoil. Then everywhere, the citizens, obliged to defend themselves against the world minority of revolutionaries, will exterminate those destroyers of civilization, and the multitude, disillusioned with Christianity, whose deistic spirits will from that moment be without compass or direction, anxious for an ideal, but without knowing where to render its adoration, will receive the true light through the universal manifestation of the pure doctrine of Lucifer, brought finally out in the public view. This manifestation will result from the general reactionary movement which will follow the destruction of Christianity and atheism, both conquered and exterminated at the same time.4

WWIII will not happen so long as America maintains dominance and forces everyone to be peaceful.

America, on the contrary, provokes conflict.. who broke the peace in the Middle East provoking the Arab spring? So do not make people laugh!