Anyone who really believes that the USA Federal Government involved itself in to two world wars at tremendous cost to its citizenry for the sole purpose of greasing the arms of its industrial complex is exceedingly cynical.
Those who push this line clearly have no love of democracy, as without the involvement of the US in these two world wars, freedom and democracy as we know, would have been crushed under the Nazi boot and the Japanese samurai.
If we are discussing wars, other than the two world wars of last century, well that's a different story altogether.