Is a world war imminent?

Consider this:

Iran is testing nuclear weapons almost daily. Israel is preparing a defense and has already started actively moving militia. It doesn’t take long for these things to build. I look at it like this, North Korea wants to attack South Korea… China wants to take over Taiwan… The United States is already fighting two “wars, conflicts”… Russia has already shown their interest in war by invading Georgia, the country, in August. What better time for other countries to begin war rather than the time that there strongest opponent, the US, is tied up in two other wars. Russia obviously has the power to do things, China has shown greedyness in taking over Tibet and have clear growing intentions, and Iran is a ticking time bomb. All of those countries could easily form an alliance and begin “the Last Great War”. The reason I say last is because in the event that there is another great war, it is likely humanity will end. Even though it wouldn’t make sense to knowingly start a nuclear fallout.