What kind of regulation do you have in mind?

The government controls the algorithm? Then the government pushes propaganda.

The algorithm is public? Then what kind of public algorithm? "Sort by recency", "sort by popularity", etc. will be gamed by propaganda-pushers. "Sort by closest friends" is better, but I suspect even it will be gamed by adversaries who initially push genuine interesting content and encourage you to befriend them, then shift to propaganda.

Sorry to be cynical, but I doubt you can prevent people from being attracted to and influenced by propaganda; if necessary, well-funded organizations will hire paid actors to meet people in person. You must narrow the goal, e.g. can hinder foreign propaganda by down-weighting accounts from foreign IP addresses, detecting and down-weighting foreign accounts which use residential VPNs, and perhaps detecting and down-weighting domestic people who are especially influenced by foreign propaganda to the extent they're probably being funded (but you don't know, so then you get controversy and ambiguity...)

Reverse chronological + subscription (ie. the user must actively make a choice to follow some channel or creator to get them in their feed). This is how most platforms started, and while there were still issues (eg. rewarding frequent posting) they seemed a lot less problematic than what we have today.

The main issue isn't the misinformation or disinformation; it is how quickly you can amplify reach and reach millions. Reverse chronological + follows based on active user choice would largely address that issue.

I'm no political scientist, but I believe in checks and balances. It translates roughly to costly burocracy, but if the next president or Congress will face significant pushback either from each other or the judiciary, and if the democratic institutions are strong, then we can trust that a reasonably well structured law will prevent by itself abuse.

The law is abused in the US because they have the tradition of keeping the constitution to a bare minimum and govern by precedence and common sense, which as we can see isn't very productive.

So yeah I guess I'm advocating for burocracy for now, at least until someone comes with a better idea. I'd take burocracy many times before corporation abuse.

EDIT: now I see I haven't addressed the main question. I believe that society needs a mechanism to hold big tech platforms accountable for abuse. The speed which big techs can push certain kinds of information through their services is such that the due process, when it works, is only effective after damage is done and by then different accounts and different outlets are already pushing the same kind of disinformation ads. Therefore preemptive removal of this content is necessary. The problem now becomes how to make it so that the universe of content eligible for preemptive removal can't be abused by the current administration. How can we make it so that the Israeli misinformation machine can't overshadow other institutions, but at the same time guaranteeing that the next political party in power can't abuse this system to suppress valid propaganda from the opposition?