On one extreme of the liberal narrative, war, like firearms, is an innate evil. It is said to occur because politicians and businessmen get together in one secret room and decide to puff up their profits and political fortunes with jingoism and a military campaign. The fancy name for this particular conspiracy theory is the military-industrial complex.
Most rational conspiracy theories do require a profit motive, but it might be worthwhile to ask, do politicians really profit from war? In American history, the history of the same country blamed for much of the 20th century's wars, fighting a major war has been a virtually certain way to destroy a Presidency. In the 20th century, four Presidents, Woodrow Wilson, Harry Truman, Lyndon Johnson and George W. Bush, had their presidencies destroyed by four of the five major American wars of the 20th century, WWI, the Korean War, the Vietnam War and the War on Terror.
Not only did these wars severely damage the individual reputation of the President in question at the time making them political pariahs, but in each case they resulted in the transfer of the Presidency to the rival party. The only President to escape this trend is FDR over WW2, who died in office. This is not a track record that would encourage any President to engage in a major war. It is a track record that would encourage a President to steer clear of any wars, and if inheriting one to bail out with a facesaving truce as fast as possible, the way that Eisenhower and Nixon did.
War is therefore clearly not of political benefit to a President. Nor to his party. The safest thing to do politically, is to avoid all wars. To issue broad generalities about a desire for peace with everyone. It will alienate many people who are concerned about emerging threats overseas, but it will unite the mushheads behind you, and it is worth remembering that mushheads are a far more vital demographic, than people who think in terms such as sacrifice and responsibility.
Not fighting a war is always safer, because American wars are usually fought to deal with threats that may only metastasize decades or even generations later, when the Commander in Chief is playing golf in a charity tournament and safely out of office. Take the Korean War, unpopular at the time and condemned as unnecessary, which took nearly 50 years to turn into a direct threat to the United States. Yet had the Korean War not been fought, Kim Jong Il would have had all of Korea to play with in order to develop weapons of mass destruction, and the millions murdered, tortured and brutalized can only be imagined. In turn had men like Douglas MacArthur and Curtis LeMay been listened to, Kim Jong Il and his nuclear arsenal would not exist at all.
From a President's standpoint therefore, war is a destructive thing politically, but can be vital from a long term perspective that may not be appreciated at the time. It took until after the end of WW2 for the general American public to understand why it had to be fought, regardless of Pearl Harbor. The Korean War as we have seen has taken far longer to be justified. The Vietnam War may never be justified in the context of liberal historical revisionism that continues to insist that Communism was never a threat. The War on Terror will not be justified until the next major terrorist attack hits home.
It is much safer therefore to fight a War on Poverty, a War on Pollution, a War on Obesity, or a war on anything that only requires moral hectoring and principled pork, with nary a rifle in sight.
What defense contractors prefer is a steady defensive arms buildup which enables them to profit from the pork, without having their products actually be field tested. Which is why the defense industry loved the cold war, but dislike hot wars. Cold wars bring in lots of no pressure orders. Everyone has a field day guessing what the enemy is developing, and what needs to be developed to counter them. None of it really matters, because it is never meant to really see action. Much like the Minutemen missiles, which have a failure rate that it's best not to even think about.
So what is war good for anyway? The unpopular and much reviled answer, is that American wars are good for protecting America and the rest of the world. The United States has not launched a single war of territorial conquest or unprovoked aggression in the 20th century. American forces have at one time or another captured much of the world's territory, across Europe, Asia and the Middle East-- and given it all back after a rebuilding program that benefited the region's inhabitants, at America's expense.
Had America really been in the business of spilling blood for oil, as the cynical left wing shriek goes, why aren't Kuwait and Iraq, American protectorates? Why for that matter are South Korea and Japan, two of the richest places in the world, free states with independent and often contradictory foreign policies? If the accusations of the left held any truth to them, the world should be an American Empire that would cover some of the richest markets in the world, including Japan, Germany, France, South Korea, Kuwait and Lebanon. Yet for all the blather about an American Empire, no country has been more unwilling to seize territory in the 20th century than the United States, despite having every opportunity to do so.
Very few would have blanched had the United States chosen to carve up Germany after WW2, the way the USSR did to much of Eastern Europe. With all the criticism America has faced over its actions in Iraq, it would have faced no more, had it followed suit and discarded rebuilding, in favor of permanent colonial rule. Yet the United States did no behave as the empire that its foreign and domestic enemies portray it as. Instead the United States has fought wars that have given without taking.
War does not profit the United States. War has never profited the United States. It has been a necessity born out of a need to prevent the rise of new terrors and tyrannies, to combat evil, and to do the right thing.