'The way we think about our work changes our work' is a reflection of our attitude towards the work we do. Some people view their job/work as a simple means of making money to pay all the necessary bills. They are not enthusiastic about it and sens it a duty, a task that has to be performed during the week. Apart from money, they don't see any benefits of doing this particular job. Other people have a different mindset, even if they are not 100% satisfied with their current occupation, they always try to see something positive in it. For them, it may be just a step on their carrier ladder or a place where they can meet new friends. They are usually more grateful about having a job in the first place.
What Dan Pacholke is trying to say is that our mental attitude toward the job makes us enjoy or hate it. So even a boring job may have some hidden benefits if only we want to see them. By being positive about our job we gradually learn to enjoy it more.
In my own life, this statement could apply to learning. If I see studying as a boring and useless task, the studying process will become a boring and useless task for me and I would not enjoy it. On the other hand, if I try to see learning as a way to gain new knowledge and become wiser, I might actually enjoy learning and look forward to doing it.
to keep us neatruel and not get involved in any wars
he assumed control of treaty negotiations with a hostile power