Greatest War Invention

That depends how you define great.

Great as in powerful and almighty, you can't really argue with the tank when you got bad boys like the Arbrams :tank: . But then again I guess the greatest weapon of all would be the nuclear bomb, giving man the capacity to end the world as we know it within hours.

If you mean great as in serving a moral and virtuous purpose, the helicopter for quick extractions of the wounded within the golden hour takes the cake.

If you mean great as in all totally sick and cool, this ones really up in the air. So many things, I can't choose one. Flamethrower, .50 cal, fighter jet, aircraft carrier, nuclear submarine, I could go on forever.

the All-Volunteer Army, hands down. When you have an army of soldiers that WANT to be there, you have a more professional army that takes (IMHO) more pride in what they do and how they serve. All the Nuclear submarines and fighter jets and tanks would be inconsequetial without highly motivated, well trained and fully capable crews manning them.

Just my two cents.
Actually, I think it may even go beyond that, to the concept of "dulce et decorum est pro patria mori." ("it is a sweet and honorable thing to die for your country")
Getting naturally selfish humans to give their lives for the good of their country rather than their own gain/personal defense is quite a concept if you think about it. Not of course that I believe that any death is "dulce," death and sweetness kind of cancel each other out in my book.
Gun Powder. Being able to hit your enemy when he cant hit you is the escense of modern war :rambo:

Keep in mind where not talking conceptual ideas like leadership and will, this is straight fighting material.
In the realm of concepts, I agree with Dragon_Master_Gunner and the all volunteer armed forces :)

In the realm of pratical fighting stuff: indirect fire - the true meaning of hitting an opponent who can't see, or hit, you.

And if we are talking sick stuff, FutureRANGER, don't forget antipersonnel mines, booby traps, poison gas and biological weapons :x
I meant sick as in healthy as in bad as in good as in COOL. lol sorry should have made that more clear :lol:

Sick as in amoral and inhumane as you mean, you're right those are all terrible. Everything is terrible. :rambo:

But tanks are COOL :tank:
And everyone can say it with me "The stuff we don't know about yet!" AS far as stuff we do know about I would say laser satellites and whatever material they made the bunker buster out of.
As far as actual material objects, I think the Tank/Fighting Vehicle is/was the greatest invention: being able to move over any terrain, engage the enemy with overwhelming firepower, and under armor.
I think morale is key... if your soldiers have high morale and something worth fighting for... watchout - especially if your opponent doesnt. Uh-Oh! :twisted:
The internet was originally began as a communication network with self routing ability that would allow it to route messages around damaged nodes.... for the military.
Sooooo, the internet.