Taking the Saudi war as an example, we could say that by any reasonable assessment, the U.S. government should have stopped providing direct military support to the Saudi Arabia-led air campaign in Yemen, on the day after it started. Washington's participation began in March 26, 2015 when a White House spokesperson announced "President Obama has authorized the provision of logistical and intelligence support to (Gulf Cooperation Council) -led military operations ".
The United States have become a willing co-combatant in a war without any direction or clear end state.
So yes, it is responsible for wars over the decades.
The U.S. continues to arm, train and provide essential logistical support for the air campaing in Yemen because this support has occurred during both Democratic and Republican administrations, as we learned in Vietnam previously, and Afghanistan every day , where poor strategic decisions are made and sustained by administrations of both major political parties.
Its support has never prevented the killing of innocent people.