Every year, the government publishes a report on the operation of the National Security and Investment Act. It sets out how many transactions were notified, how many were called in for assessment, which sectors attracted the most scrutiny, how many interventions resulted, and the patterns in the decisions made. The report is read closely by a small community of M&A lawyers and transaction advisers, and largely ignored by everyone else.
This is a mistake. The NSI Act annual report is, for any organisation operating in or supplying critical national infrastructure, one of the most useful intelligence documents the government produces. It is the closest thing available to a published map of where the government's actual national security concerns lie, expressed not in the abstract language of strategy documents but in the concrete record of which transactions it scrutinised and which it stopped. Read correctly, it tells CNI operators and their suppliers more about the real contours of national security policy than any speech, white paper, or strategy refresh.
Stated Priorities and Revealed Priorities
There is a difference, in any area of policy, between stated priorities and revealed priorities. Stated priorities are what the government says matters: the sectors it names in strategy documents, the threats it identifies in speeches, the concerns it articulates in published frameworks. Revealed priorities are what the government actually acts on: where it commits resources, where it intervenes, where it accepts cost and friction to achieve an outcome. The two overlap but are rarely identical, and the gap between them is where the most useful intelligence lives.
For national security and investment, the NSI Act annual report is the document that reveals the revealed priorities. The Act gives the government the power to scrutinise and intervene in transactions on national security grounds, and the annual report records how that power was actually used. Which sectors generated the most call-ins. Which kinds of acquirer attracted the most scrutiny. Which transactions were blocked or subjected to conditions. This is not the government saying what concerns it. It is the government showing what concerned it enough to act, across hundreds of real decisions.
The revealed priorities frequently differ from the stated ones in instructive ways. A sector that features heavily in strategic rhetoric may generate few interventions, suggesting the concern is more political than operational. A sector that attracts little public attention may generate a disproportionate share of call-ins, revealing a concern the government has not chosen to articulate publicly. The pattern of acquirer nationalities subject to scrutiny reveals which relationships the government actually treats as sensitive, as opposed to which it discusses in those terms. The report, read for the gap between revealed and stated priorities, is an intelligence document of real value.
What the Report Tells a CNI Operator
For a CNI operator, the report carries specific and actionable intelligence about the operator's own strategic environment. It indicates where the operator's sector sits in the government's actual national security concern. A CNI operator in a sector generating high call-in volumes is operating in an environment the government is watching closely, with implications for the operator's own transactions, its supply chain relationships, and its strategic options.
It signals the transaction patterns most likely to attract scrutiny, which matters for any CNI operator contemplating acquisition, investment, divestment, or significant supply chain change. The report's record of which transaction types, deal structures, and acquirer characteristics generated call-ins is a guide to how the operator's own contemplated transactions are likely to be treated. An operator planning a transaction that matches the profile of frequently-called-in deals can prepare for scrutiny in advance, structure the transaction to address the likely concerns, and avoid the cost and delay of an unanticipated intervention.
It reveals the government's concern about the operator's supply chain. The NSI Act increasingly captures transactions involving suppliers to CNI, not just CNI operators themselves. The report's record of supply chain interventions tells a CNI operator how exposed its supply base is to NSI scrutiny, and where the operator's supply chain intersects with the government's national security concerns. This is intelligence about the operator's own dependencies, derived from the government's behaviour toward them.
What the Report Tells a Supplier
For a supplier to CNI, particularly one with non-UK ownership or investment, the report is even more directly consequential, because the NSI Act is, for such suppliers, frequently the primary constraint on market access. A supplier with non-UK ultimate ownership contemplating acquisition of, investment in, or significant contracts with UK CNI is operating in the NSI Act's domain whether it recognises this or not. The report tells such a supplier how the Act has actually treated transactions like the ones it is contemplating, and a supplier that reads the report can assess its NSI exposure before it commits to a transaction rather than discovering the exposure when the transaction is called in.
The report also reveals the trajectory of the Act's application, which matters for suppliers planning over a longer horizon. The Act's scope and the government's appetite for intervention have evolved since it came into force, and the annual reports, read in sequence, show the direction of travel. A supplier can see whether scrutiny in its sector is intensifying or relaxing, whether its acquirer profile is becoming more or less sensitive, and how the government's concern is developing over time. This longitudinal intelligence is available nowhere else, and it bears directly on the supplier's strategic decisions about the UK market.
How to Read It
The report rewards a particular kind of reading, and most of the value is missed by readers who treat it as a compliance update rather than an intelligence document. The aggregate figures matter less than the patterns within them. The total number of call-ins is a headline; the distribution of call-ins across sectors, acquirer types, and transaction structures is the intelligence. A reader who notes the total and moves on has missed the document's value.
The changes between reports matter as much as the contents of any single report. The first NSI Act annual report established a baseline. Each subsequent report reveals movement: sectors rising or falling in the government's concern, acquirer profiles becoming more or less sensitive, the Act's application broadening or narrowing. Reading the reports in sequence, and attending to the deltas, reveals the trajectory of national security policy in a way that no single report can.
The silences matter too. What the report does not mention, the sectors that generate no interventions, the acquirer profiles that attract no scrutiny, the transaction types that pass without comment, is itself intelligence, revealing where the government's concern is absent. The NSI Act annual report will never be a bestseller. But for the organisations whose strategic environment it describes, it is among the most valuable documents the government publishes, because it reveals, in the concrete record of actual decisions, the national security priorities that the government acts on rather than the ones it merely states.