Who Decides What Enters the Ethereum Block? An Audit of a Question That Won't Die

There is a question that surfaces in Ethereum discourse with the regularity of a scheduled audit finding: who, precisely, decides whether a transaction is included in a block? It is a question that sounds technical but is fundamentally a governance stress test. A recent commentary piece has posed this question again. It offers no data, no new mechanism, and no proposed EIP. By most conventional analysis metrics, it is a null event. That, however, is precisely why it warrants a closer look. In my years auditing protocol risk, I have learned that the absence of a solution is often a signal, not a silence. When this question re-emerges without an answer, it is not a query; it is a symptom of an unresolved systemic tension. The article does not tell us who decides. It tells us that the market is again uncomfortable with the current answer. This is a forensic review of that question, the structural forces that keep it alive, and why it remains a ticking liability for the network. The ledger bleeds where emotion replaces logic, but it hemorrhages when a foundational governance question is left to fester. For the uninitiated, the query 'who decides what gets on-chain' is not about network capacity. It is about the transaction inclusion rules within the block building pipeline. Today, the answer is not the Ethereum protocol itself, but a semi-centralized market of specialized actors. The introduction of Proposer-Builder Separation (PBS) and the MEV-Boost middleware created a default pipeline where the majority of validators outsource block construction to professional builders. This was designed to combat the destabilizing effects of MEV, but it created a new dependency. The builders now hold the de facto power to include, exclude, or reorder transactions. This is the black box of Ethereum transaction flow. The 2022 OFAC sanctions against Tornado Cash turned this theoretical power into a practical precedent: several builders began filtering transactions from sanctioned addresses to protect their own compliance status. This created a real, observable chain of technical censorship. It was a violation of the 'credible neutrality' ethos that underpins the network's value proposition. The community's response was the 'Inclusion Lists' proposal, a mechanism to let validators force-builders to include specific transactions. It was discussed, debated, and ultimately shelved. It remains unimplemented, a ghost in the machine. Here is where the analysis shifts from history to autopsy. The recent article's failure to provide a new technical solution is not a weakness; it is an accurate reflection of the problem's complexity. A superficial reading dismisses it as noise. A risk-management frame reads it as a warning that the previous band-aid is failing. The core issue is that the technical question of 'who decides' is being conflated with an operational one. The article parsed the issue as a choice between 'builders decide' or 'validators decide.' This framing is the first flaw. It assumes a binary agency where one actor has the power. In reality, the power is diffused across a supply chain: the builder commits to a block; the relay validates it; the proposer signs it. The failure point is the implicit trust placed in the builder. A forensic teardown of the existing system reveals that the status quo is not designed for censorship resistance. It is designed for economic efficiency. We have optimized for MEV extraction and block quality, creating a system where builders are rewarded for being 'good actors' via a competitive market. But 'good' is defined by the relay's rules, which are influenced by legal pressures. The market incentivizes compliance over neutrality. This is the hidden structural risk. The protocol does not enforce neutrality; it hopes for it. This is not a foundation; it is a hope. Based on my work auditing stakeholder behavior, I can tell you that cultural adherence to 'credible neutrality' degrades proportionally to the value of the private order flow. As the DeFi ecosystem matures and institutional actors enter, the demand for compliant transaction flow will only increase, applying more pressure to builders to self-censor. The second layer of this issue is the governance vacuum. Ethereum has no single authority that can answer the question of 'who decides.' There is a distributed governance process involving the EIP flow, core developer consensus, and validator signaling. This process works well for addressing bugs or incremental upgrades. It is structurally incapable of resolving a conflict between legal compliance and protocol neutrality. The article's lack of a 'subject' in its question is telling. Who exactly is meant to answer? The core developers? The staking community? The application layer? By not specifying, the article highlights that no one is empowered to make that decision. If we were to take the proposal seriously and implement a protocol-level mandated Inclusion List, we would be forcing a legal conflict onto every single staker. A validator in the United States would be compelled by the protocol to include transactions that the Office of Foreign Assets Control (OFAC) has explicitly prohibited them from facilitating. This creates a direct 'law vs. code' conflict. It shifts legal liability from the institutional service providers (like Coinbase and Lido) down to the individual validator. This is not just a technical upgrade; it is a systemic risk transfer. Unsurprisingly, the probability of a protocol-level enforcement mechanism being adopted is incredibly low. The status quo remains a messy compromise: 'We retain the technical capability for neutrality, but we keep the procedural mechanisms weak to avoid legal clarity.' This is a liability management strategy, not a principled solution. Let us address the regulatory dimension, because this is where 'institutional risk calibration' fails for most retail commentators. The narrative is that 'crypto wants to be free.' The reality is that the infrastructure wants to be legal. If Ethereum were to hard-code censorship resistance into its base layer, it would explicitly advertise itself as an adversarial system to Western regulators. The current ambiguity is actually a massive regulatory shield. It allows spot ETFs to exist and institutions to participate because the protocol itself is not 'actively' breaking the law; it is just failing to prevent specific actors from doing so. If the protocol were modified to guarantee transaction inclusion, it would cross a bright line. It would give regulators the justification they need to classify the network as a 'security' or a 'money laundering concern.' The article's discussion of 'who decides' is a proxy for 'who is responsible?'. By avoiding a solution, the article is implicitly acknowledging that no one in the ecosystem wants to accept responsibility for the outcome. They prefer the risk to remain opaque. In my consulting experience, this is a classic 'tragedy of the commons' situation. Everyone benefits from a neutral protocol, but no single actor can justify the cost of implementing it if it means legal exposure. The collateral damage is the smaller, independent entities that cannot afford institutional compliance teams. They are the ones left holding the bag when a transaction is rejected. Now, for the contrarian angle. The 'bulls' on protocol-level censorship resistance, whom I often dismiss as idealists, have one critical data point on their side. The status quo is not neutral; it is merely quietly centralized. We already have a peer-to-peer network where a dozen or so builders handle a majority of block production. That is a single point of failure. By ignoring this and praying that market incentives will keep these actors honest, we are accepting a hidden centralization risk. A move to forced Inclusion Lists would decentralize the 'right to participate' in Ethereum. It would make the system more robust by ensuring that even the most politically unpopular transaction can be submitted for inclusion. This is a massive value proposition for DeFi. DeFi protocols are essentially 'a set of rules that anyone can use without asking permission.' If the base layer allows for arbitrary censorship of inputs, the financial logic of DeFi collapses. It becomes a glorified clearinghouse with extra steps. Therefore, the bulls are right: the ambiguity in the current situation is not a middle ground; it is a ticking time bomb. The recent article's existence is proof that the market is starting to price in this tail risk. The risk is not that a fork happens; the risk is that a major sanctioned event occurs, a builder filters it, and the market loses faith in the neutrality of the entire settlement layer. That is an existential risk, not a market risk. Where does this leave us? The takeaway from this re-opened question is not to propose a solution. It is to stress-test the foundation. The question 'who decides' is not a technical puzzle to be solved; it is a political compromise to be monitored. The practical action for an analyst is to track the indicators of this compromise breaking down. I will be watching three specific signals. First, the Ethereum core developer forums for any new EIP that revives the Inclusion List concept. Second, the geographic distribution of staking entities, specifically monitoring if US-based validators become a majority. Third, and perhaps most importantly, the public regulatory stance of large staking services like Lido and Coinbase. If they formally adopt a 'compliance first' policy for transaction inclusion, the argument for protocol-level guarantees becomes stronger. Hype is a liability. Action is data. The ledger bleeds where emotion replaces logic, but it balances when audited properly. The next correction in this market may not be a price crash; it will be an infrastructure crisis. The question is not whether you can buy a token; the question is whether your transaction will be allowed to settle. That is the final audit, and we are not ready for it.