"The ultimate management challenge is responsibility without authority." I was told that within the first year or so of my career, i.e. early 20's, and it's stuck in my head 30 years later (and quoted many times along the way!). It turned out to be somewhat prophetic for me as I kept ending up in jobs where my ability to accomplish objectives often required contributions from people over whom I had no authority. I like to think I did pretty well at that... My approach was pretty simple -- earn the respect needed overall as an individual as well as specific to the challenge. If what you're doing is logical and is consistent with the goals of the organization -- i.e. "yup, that's a great idea" -- it's much easier to be persuasive. "Persuasion" is a neutral term -- the simple act of getting others to agree with you. It's the intention of persuasion where things get ugly --- "manipulation" is a not-so-neutral term and note that some will argue that some manipulation is in the best interests of others, but I'm kind of slow to drink kool-aid.