Command of the sea or control of communications? Adjudicating Mahan and Corbett in a chokepoint crisis
A maritime planning cell has three weeks to frame advice on a limited maritime confrontation. The adversary's battle fleet outnumbers the cell's navy 28 major surface combatants to 14, and 11 submarines to 6. However, 85 per cent of the adversary's seaborne trade - including 70 per cent of its crude imports - passes through a single strait about 40 nautical miles wide, and its escort force is already committed to convoy duty there. The political directive forbids striking first, caps the air campaign at 40 sorties a day, and rules out attacks that risk civilian casualties in littoral towns. Three factions form: one demands a decisive fleet action on Mahanian lines; a second insists that only the destruction of the enemy's trade can coerce it; a third argues for keeping the fleet in being and ceding nothing. The cell's own logistic support lasts 21 days without resupply, and two of the six submarines are in refit.
1. Which of the three positions best fits Corbett's theory of maritime command, and why does the Mahanian option fail under these constraints?
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Framing the distinction. Corbett treats command of the sea not as a trophy won once in battle but as a relative, temporary condition exercised over particular lines of communication. Mahan's decisive battle is a means that becomes rational only when the battle fleet can plausibly win and when the enemy fleet is the true centre of gravity.
- Ratio test. At 28:14 in surface combatants and 11:6 in submarines, a sought engagement risks destruction of the cell's fleet; after that the strait becomes irrelevant because nothing remains to contest it. Mahan is not wrong in the abstract - he is inapplicable at this correlation of forces.
- Where the vulnerability actually sits. Concentrating 85 per cent of trade and 70 per cent of crude through one 40-nm strait is exactly the 'communication' Corbett says navies exist to control and interrupt. Denial there imposes cost without requiring battle-fleet parity.
- Fleet in being, correctly used. Corbett and Richmond both insist a fleet in being is a threat, not a shelter. The fleet must sortie enough to pin the adversary's escorts; passivity converts a threat into an absence.
- Constraint check. Twenty-one days of logistics and two submarines in refit cap the operation at a denial campaign, not a command campaign.
Conclusion. The Corbettian denial posture fits; Mahan is misapplied here, and 'fleet in being as inactivity' is a corruption of Corbett rather than an application of him.
2. One syndicate invokes Sun Tzu's dictum that supreme excellence is to subdue the enemy without fighting in order to justify an unrestricted commercial blockade. Assess this use of the text.
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What Sun Tzu actually argues. The dictum sits inside a passage about attacking the enemy's plan and alliances before attacking his armies and cities. It is an argument about the ordering of effort and the avoidance of costly siege, not a licence to substitute economic pressure for strategy. Using it to bless a blockade inverts its logic: a blockade is a slow, attritional instrument, not a bloodless shortcut.
Three misapplications.
- Force against civilians. A close blockade coerces a population, not a fleet. It engages the law of naval blockade (effectiveness, notification, impartiality, proportionality) and Article 41/42 logic on coercive measures short of force - questions the dictum does not address.
- The rally effect. Corbett and the First World War experience both show that blockade consolidates the adversary's will before it fractures it; the coercion is real but arrives late, and 21 days of own logistics is not a late-arriving instrument.
- Category error. Sun Tzu's economy-of-force argument is about avoiding engagement you cannot win; it is not a theory of maritime denial. Quoting it to justify a course of action here is ornament, not analysis.
Judgement. The correct use of the dictum is to argue for limited aims - denying the strait rather than strangling the economy - so that the political objective stays proportionate to the military means.
3. The cell is told to nominate the single additional fact that would most efficiently overturn its recommendation. What should it be, and why is it more decisive than the alternatives?
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Test for 'most efficient'. The fact must (a) be observable before commitment, (b) sit on the causal chain between denial and coercion, and (c) not be something the cell can simply adapt to.
The strongest candidate. Evidence that the adversary holds an overland pipeline route plus roughly six months of crude reserve. Denial strategy works by running the adversary's stocks down inside the political timeline; if stocks and alternative routes exceed that timeline, the strait stops being leverage and becomes only a tripwire. The whole recommendation rests on the strait being the adversary's critical vulnerability, so a fact that breaks that premise is fatal rather than inconvenient.
Weaker alternatives, for contrast.
- Two more submarines available: changes the attrition calculus but not the logic of denial.
- Strait lies outside own fighter cover: serious, but it degrades execution rather than the concept, and can partly be answered by submarine and mine warfare.
- High share of neutral-flagged traffic: raises legal and diplomatic cost, yet still leaves a narrower denial option.
Conclusion. The cell should name the reserve-and-pipeline fact, because it attacks the single load-bearing assumption - that 85 per cent of trade through one strait equals coercive leverage within the available political and logistic time.