Discounting the prospect of a massive war in the future is not wise. On the other hand, warmongering or believing WW3 is a significant prospect is, as you said, not serious. There is far more interest in limited intrastate conflict these days -- because it can be profitable -- than grand conflicts. It is not a coincidence that we have not witnessed another world war since 1945. It is not merely that states do not wish to repeat such a thing (although it is true that the LIO has progressed immensely since, and the incentives for a grand war are no longer there from a trading, economic and technologic perspective), but also that there is now the spectre of nuclear weapons over everyone's heads. Nuclear weapons have saved humanity from the worry of another WW3. I am not saying it might never happen, but that it is very unlikely to happen any time soon. Not only is a nuclear war unlikely, so is WW3 in general. 

The OP needs to read on theories of escalation and de-escalation, limited warfare, revolution in military affairs, proxy wars, and of course the history of the Cold War and the post-Cold War period. 

That is my predisposition as well. Maybe he is not 10, but he does not sound like an adult at all. If he is an adult, he should take this as an opportunity to educate himself a bit before attempting a serious conversation on topics he does not understand adequately.

Maybe you are not, maybe you are. The fact is that you do not comprehend essential strategic aspects of the topic, from deterrence and rational actor theory, to what a proxy war is. Being fascinated about war is fine (if a little bit stupid), but in order to participate in a serious conversation about it you need to expose yourself to more than just media and forum discussions. People on fora rarely know what they are talking about. You are not an exception by all means.

Well too bad only few people discussing this seriously, except  you,  most of post are like " I don't want war!"  " bla bla bla" . So i am not going to discuss with that kind of people. My intention clearly want to discuss how US or Russia will engage in Arena war etc etc. How powerful both of them, what if US bring allies to the conflict will they win?

Because you seem the expert here i want to know from you.

Sounds like someone who could crash an airplane at the World Trade Center with a smile anytime... 

Sound like you like to play Video games , having guns , like to trash someone, but afraid in real war. pathetic  

no guns / lifes wasted here

Hopefully you are joking because war is never good. Also there was no world war 3 during the cold war so I think we'r just going to go through a cold war 2.

Yes for example global warming and terrorist groups are really scary right now.

Did i mentioned in OP that  want war??? I am just predicting the outcome of Trump attack in Syria. And World war 3  is not equal Nuclear War. 

so still alive,no ww3, we good.

we'll get to play god of war still

First I think you mean imminent and not eminent

And to answer your question, war is not a sport or a competition where you need to score to win or to challenge yourself, war is about winning by force and if you are invaded or attacked you will use any means at your disposal to defend yourself and counter attack. That is why nukes will most certainly play their part should WW3 break out.