Back when I was serving in the Air Force, one of the important principles that they drilled into all personnel — regardless of whether they were pilots — was “situational awareness”. For the pilots, this could be a matter of life and death as they had to be constantly aware of their environment to any possible dangers. Other than the obvious dangers of being engaged by enemy aircraft, there was also the challenge of keeping that chunk of metal in the sky!
Dangers can be posed by terrain, engine failure, inaccurate instruments, etc. For the non-pilots, the emphasis was more on safety — personnel and equipment safety. Any mistakes made during training or operations can result in expensive equipment being damaged or personnel (who are also expensively trained) being hurt.
In the context of project management, it will help to keep one’s ears up and have your personal “radar” switched on to detect if there may be any factor that can affect the success of your project. Possibly a merger with a larger competitor which already has implemented something you are working on? Some other project that senior management has initiated and will take resources away from your project? Some key personnel who are vital to your project’s success leaving the organization? These are undoubtedly factors that can contribute to the success or failure to your project and will have to be highlighted as risks if you want to keep the project on course.
You should not be shy to approach the steering committee or project sponsor if you feel that the project is coming to a point where it may be canned. It can still be considered a success if you practice situational awareness and pull precious company resources and time from a project in a timely fashion once you have confirmed that the project is no longer viable.