The History Channel produced the graphic at the bottom to go with their documentary 'The World Wars' which shows the 'War to End All War' in numbers which was the first air war as well as the first as the first to use chemical weapons and tanks on a large scale. An estimated 14.6 million were killed (8 million soldiers and 6.6 million civilians).
We still live with it's consequences today and it's hard to find anything good that came of the war for anyone. What attention there is on WWI in the US has mostly focused on how men like Hitler, Churchill, Mussolini, and Stalin, who were prominent in WWII, became battle hardened during it and rose to power in it's aftermath.
Less reported is how the Middle East was carved up after the British and French seized it from the Ottoman Turks. By the Sykes-Picot agreement Syria and Lebanon became colonies of France while Iraq, Jordan and Palestine fell under British rule. Winston Churchill became secretary of the colonies and brutally put down rebellions by the Kurds in Iraq. This conquest was later glorified in films like Lawrence of Arabia. British Petroleum (now BP) was created in this period.
Today Iraq is being carved up by the Islamic State of Iraq and Syria with funding from Saudi Arabia. The third picture above shows the lands in Iraq and Syria that they control. Robert Fisk of the Independent reports that this is the beginning of the end for the Sykes-Picot agreement. Saddam Hussein in Iraq, the Assad family in Syria, Kings Hussein and Abdullah of Jordan, and of course Israel have all done their part to brutally hold it together but it is a shotgun marriage that could not last forever. Saddam Hussein became a pariah when he violated the Sykes-Picot agreement by invading Kuwait Iraqi Sunnis are now abandoning their army and joining ISIS while Iraqi Shiites are likely to side with Iran.
George W. Bush's 2003 invasion of Iraq created a power vacuum in Iraq which ISIS was finally able to exploit just as Hitler and Stalin were able to capitalize on in their countries after WWI (the History channel documentary on the world wars interviewed the top hawks from the Bush administration such as Cheyney, Rumsfeld and Powell plus Senate hawk John McCain). How all this will play out is anyone's guess with the US, Iran, and other outside powers weighing their options. With an estimated hundreds of thousands (the precise number may never be known) dead in Iraq and Syria since 2003 could this be a resolution or an escalation of the conflict? I don't know the answer to this question but the less further bloodshed there is, the better for all sides.