ww1 never should have happened. It was an interventionist war to begin with.
The Ottoman Empire should definable not have been broken up, it would have dissolved more peacefully. There would never have been an Iran Iraq war, the Kurds would likely have their own state. Neither would Israel be experiencing much of her problems

The US had no control over whether WWI happened or didn't happen. The fact is that it did, but I'll agree that we should have never become involved in it. There are worse things that could have happened than to have imperial Germany gain hegemony over northern Europe. In fact, worse things did happen, and they happened less than two decades after Germany had been ground under the heel of the Allied powers, including the US under President Woodrow Wilson. The rise of the National Socialist Party in Germany in was directly attributable to post-war conditions in Germany. Without the Nazis, there would have been no Holocaust and therefore no pressure to provide European Jews with a homeland outside of Europe after a second world war that never would have happened.