It is very easy to look at those you don't frequently interact with as "the others." Even if you are on the same team working towards the same goal, you can start seeing them as the antagonist to what you and those around you are trying to do. Your squad may fervently believe in a new feature, system, or tool, but those people over there just like to be killjoys and never go along. Like come on, why can't they get their crap together and see what we see?
On seriously toxic teams you may encounter people being obstinate for no reason other than to be obstinate, but if you are on a somewhat functional, healthy team, this view on "the others" is certainly based on lack of communication, quality working time spent together, and trust. Some people call this rapport. Rapport is not an easy thing to build. It takes consistent efforts over a long time to build it properly, but when you have it, it sure does make working together that much easier.
I work with an amazing example of someone who has consistently built rapport, my squad's product manager, Tim. My squad works with an external company very closely. We interface with their technology and build things that make their customers' and employees' lives easier. Tim is our main liaison between our squad and our partner's stakeholders and has made it his mission to not only know our goals and motivations but their's as well. The difference that has made has been night and day.
If you're not there now though, don't give up! Keep acting and thinking in good faith. Give "the others" the benefit of a doubt. Remember that you are still working towards the same goal, and keep showing up with them in whatever way you can, big or small. Figure out what drives them. What are their goals and motives? What is expected of them? How can I communicate what's important to them? How can I show them my appreciation for the role they play?
One way that we have bridged the gap is just by inviting our partners over to visit the office, work together, and eat together. It is amazing how many walls will lower over some tacos. Ideas that were once hesitated on are now suggested by them! They start seeking our thoughts on what to do next.
At the end of the day, remember that "the others" are people that have goals and ambitions just like you do. They aren't out to get you, and you shouldn't believe they are trying to make your life harder. Look at both the challenge and the help they bring with love and keep the faith.