In response to the title question: among other things, death, disease, destruction, misery, separation, refugees, huge bills, embittered soldiers, embittered civilians, big profits for military suppliers, and lots of propaganda and bullshit. From Kathy Kelly at antiwar.com:
At an April, 2017 Symposium on Peace in Nashville, TN, Martha Hennessy spoke about central tenets of Maryhouse, a home of hospitality in New York City, where Martha often lives and works. Every day, the community there tries to abide by the counsels of Dorothy Day, Martha’s grandmother, who co-founded houses of hospitality and a vibrant movement in the 1930s. During her talk, she held up a postcard-sized copy of one of the movement’s defining images, Rita Corbin’s celebrated woodcut listing “The Works of Mercy” and “The Works of War.”
She read to us. “The Works of Mercy: Feed the hungry; Give drink to the thirsty; Clothe the naked; Visit the imprisoned; Care for the sick; Bury the dead.” And then she read: “The Works of War: Destroy crops and land; Seize food supplies; Destroy homes; Scatter families; Contaminate water; Imprison dissenters; Inflict wounds, burns; Kill the living.”
The following week, General James Mattis was asked to estimate the death toll from the U.S. first use in Nangarhar province, Afghanistan, of the MOAB, or Massive Ordinance Air Burst bomb, the largest non-nuclear weapon in US arsenals.
“We stay away from BDA, (bomb damage assessment), in terms of the number of enemy killed,” he told reporters traveling with him in Israel. “It is continuing our same philosophy that we don’t get into that, plus, frankly, digging into tunnels to count dead bodies is probably not a good use of our troops’ time.”
His comment seemed to echo another General, Colin Powell, who, when asked how many Iraqi soldiers might have been killed by US troops invading Iraq in 1991, commented, “That’s not really a number I’m terribly interested in.” Other generals noted that some of those Iraqi troops, conscripts trying to surrender, were literally buried alive in their trenches by plow attachments affixed to US tanks. More recently, Lieutenant General Aundre F. Piggee acknowledged that during the 2007 US military surge in Iraq, when civilian casualties rose by 70%, the US military wasn’t “necessarily concerned” about limiting civilian deaths.
To continue reading: What Does War Generate?