Networks, Dependence, and Resilience

On 29 October 1888 nine powers — Great Britain, Germany, Austria-Hungary, Spain, France, Italy, the Netherlands, Russia and Turkey — signed at Constantinople a convention on the Suez Canal D [Suez Canal Authority 1888; “The World and Japan” Database 1888, the treaty text]. Article I declares the Maritime Canal free and open, in time of war as in time of peace, to every vessel of commerce or of war without distinction of flag, and never subject to blockade. Article II records that the Fresh-Water Canal is indispensable to the Maritime Canal, takes note of the Khedive's engagements to the canal company concerning it in a convention of 18 March 1863, and binds the parties not to interfere with its security; Article III extends the undertaking to the plant, establishments, buildings and works of both canals. Article VIII charges the signatories' agents in Egypt with watching over the treaty's execution, and Article XIV provides that the engagements are not limited by the duration of the company's concession D [the treaty text, Articles I–III, VIII and XIV].

The treaty draws the two graphs the worked case needs (Section 9.7 (p. 353), field 3 of the card): the passage itself, and the dependencies that keep it usable — the water supply, the works, and the right to pass. In Model K4 capacity belongs to routes, and a route is available only while every chokepoint it crosses is open: a chokepoint is a failure condition shared by the routes through it, not a capacity of its own. The convention's drafters, nearly seventy years before the max-flow min-cut theorem (Theorem 9.2 (p. 373)), listed the chokepoints that were not on the chart R.

Whether the canal was open was, by 1888, something a telegram or a company notice could say; whether the promise of passage would hold was a matter of nine governments' conduct, observable only after the fact. A modern operator sees manifests, vessel positions and queue lengths within minutes and estimates from them usable capacity, delay and arrival. That information improves the use of capacity. It cannot create a right of passage, and it cannot make two routes independent when they share a water supply, a port process or an authority. The second drawing, of the dependencies, is made from documents, not from tracking data, and it is the one that decides what the first is worth.

The treaty's text is not evidence that passage was continuously respected afterwards, and the box makes no claim about any later closure of the canal.

On 1 June 1984 the Security Council condemned recent attacks on commercial ships en route to and from the ports of Kuwait and Saudi Arabia and asked the Secretary-General to report; his report of 31 December summarised replies from governments and communications from the International Maritime Organization about incidents D [United Nations Security Council 1984, paras. 4, 7; United Nations Secretary-General 1984]. Counts depended on the counter: for 1984–87 a tabulation from Lloyd's Shipping Intelligence Unit and the Center for Defense Information gives $71$, $47$, $111$ and $179$ ships attacked, $408$ in all; one compiled from the Secretary-General's reports gives $37$, $50$, $84$ and $169$, $340$ in all D [O'Rourke 1988, Tables 1–2]. On 7 March 1987 the United States offered to reflag eleven Kuwaiti tankers and to provide US Navy protection; escort began in July, and on 24 July, on the first convoy, the reflagged tanker Bridgeton struck a mine. Three tankers struck mines that month D [Department of the Navy, Office of the Chief of Naval Operations 1991, p. 4; Mobley 2016, pp. 3–4]. The Bridgeton reached Kuwait with its escorts following in its wake, and further convoys were postponed while mine-warfare helicopters were deployed D [Cox 2018]. Resolution 598 of 20 July 1987 deplored attacks on neutral shipping and demanded a ceasefire between Iran and Iraq, which came into effect on 20 August 1988 D [United Nations Security Council 1987; United Nations Peacekeeping n.d.].

Fields 3 and 4 of Model K5's card R. Escort was attached to a declared set of ships, recognisable by their flag: visibility of that kind bears on field 3. If the whole realised allocation were observed before an attack could be chosen, Proposition 9.15 (p. 380)(b) would hold it to the guarantee of the best fixed one, whatever plan lay behind it; the cited record establishes recognisable convoys, not the observation of a full draw. Gathering ships into convoys is a choice of fewer windows, worth more or less according to the escorts available against the threat (Proposition 9.16 (p. 381)(b)). A mine does not choose its ship: it is a hazard of the lane, outside the allocation game and closer to the shared interruption of Exercise 9.10 (p. 371); the order in which the first convoy finished its voyage, the tanker ahead of its escorts, fits that reading R.

The record of attacks consisted of compilations made after the fact, whose totals for 1984 differed by nearly a factor of two. Since the end of 2004 ships of $300$ gross tonnage and upwards on international voyages have been required to carry an automatic identification system, which broadcasts the ship's identity, type, position, course and speed D [International Maritime Organization n.d.]; in 2026 transits through the strait are counted daily from these broadcasts, with a warning about jamming, spoofing and ships going dark (Section 9.8 (p. 360)). Tracking shortens the delay to the record. It does not settle what counts as an attack or who counts, the choices on which two counts of one war can differ, and it shows where ships are, not where mines are.

The box takes no position on who attacked which ship, on who laid the mines, on any party's aims, or on whether escort changed the number of attacks; no count enters the model.