"I need these permissions that J has"

J has those permissions because he worked on a different team that was granted those, you do not.

"I need it"

No

"I need it"

Its not within my power to allow you access, you have to talk with R and M.

"Okay well guess what I'm gonna escalate this up thr chain and its gonna come down on you"

*sigh* what do i do when i literally have no authority to give someone something and am clearly doing my jobb right, but someone thinks they can get me... idk... in trouble? Threaten me??? Logic, meet the window

As @Jilano said, bring it to your superior directly.

If someone is pressing for permissions in the wrong places I would call it a security risk.

Send me an formal statement why you think that you require these permissions.

I will forward them to X / Y / Z, with my strong recommendation to deny your request, since there is currently no valid reason at all to grant you these permissions and security wise it's a bad idea to grant permissions without an explicit need for it.

Way back in the day when I did tech support I found that happily 'enforcing the policy' was not useful as far as getting along with people.

If you don't have the power, don't make it seem like you are making the decision...

So I would tell them "Sorry man, I'm not allowed to give that to you even if I wanted."

"If you can convince <insert decision makers> to tell me to do it, or to do it themselves then maybe that will work."

To be clear it doesn't matter if they should or shouldn't get the thing, it's not your call so taking the flack for saying no doesn't change anything except make you seem like the obstacle.

@N00bPancakes it's really good advice. When something isn't in your scope, just say it. And if someone is trying to force you something you aren't allowed, discuss it with your hierarchy. Send a mail if you want to have proof.

Also if the company has some security policies, and very few have, it could also be a breach of the security policies...