I have been driving an international strategic initiative for more than 2 years. There was a lot of resistance initially, but I managed to align a few teams, create an MVP and a customer base.
A team in the Headquarters first showed interest in my project. They first suggested aligning my project A to their brand new project B. We prepared a joint proposal for projects A and B. As soon as we completed the discussion on customers and revenue, the proposal became "B, which happens to do everything A wanted to do". I am not being pushed out of the proposal, as it's not about my project anymore - but my customers, of course, are still there.
I worked on this project for over 2 years, and it was my main hope for a promotion. Now somebody else is going to present it to the CEO. The manager who organised this is putting pressure on my own manager to just let go. My last 2 years of work will lead to nothing. I would like to know what to do in a situation like this, and how to prevent this in the future.