12 Dumbest Decisions In MCU History

Though the civil war that caused the break up of the Avengers started with the Sokovia Accords, it was accelerated by Steve Rogers' unwavering support of Bucky. In fairness, Steve's best friend was innocent (to a certain degree) in that he wasn't responsible for the bombing at the UN or the death of King T'Chaka.

However, while operating as the Winter Soldier, though it was out of his control, he did kill Howard and Maria Stark 15 years earlier. This was something that Steve knew about, but decided to keep a secret from Tony.

Yes, Bucky was Cap's friend, but so was Tony, and since God's Righteous Man had been so offended by the lies and mistrust that flowed through SHIELD before it collapsed, you would have thought that he would have practiced what he preached and been honest with Tony.

This wouldn't have made Stark any friendlier towards Bucky, and he likely still would have wanted to kill him. However, doing so under the right circumstances, calmly and fully explaining the situation rather than waiting and letting Zemo drop the bombshell in Siberia would have likely saved a lot of fighting, and possibly even the fallout of the entire team.