At the leadership level, it’s all about finding the right decision and sticking with your choices.
Don’t get swayed because of fear and pressure if you think something is right…put all your effort into it, yes, it might fail, but at least you tried.
If your manager is a natural leader he will definitely back you up as long as your intent is good and you have put your heart and soul into making it happen.
In the end, most of the decisions will succeed only thru hard work and commitment.