TECHNOLOGY AND NAVAL BLOCKADE: Past Impact and Future Prospects
Barnett, Roger W., Naval War College Review
Anyone who wishes to cope with the future should travel back in imagination a single lifetime . . . and ask himself just how much of today's technology would be, not merely incredible, but incomprehensible to the keenest scientific brains of that time.
ARTHUR C. CLARKE
Through the centuries major changes have taken place in the ability of states to prevent the movement of ships or particular goods over the sea lanes of the world. Some of the changes have been wrought by technological evolution, some by increasing importance of seaborne trade, and some by alterations in the structure of international relations. The combined effect has profoundly affected both the way maritime blockades are conducted in the twenty-first century and the means employed for them. In large measure, it has also rendered the traditional law of blockade obsolete.
Until World War I maritime blockades were undertaken by states seeking to prevent the movement of ships or cargoes that would assist in the ability of adversaries to conduct international armed conflict. Blockade law evolved in the nineteenth and early twentieth centuries to regulate how states conducted blockades while concurrently safeguarding the rights of neutrals to use the open seas to conduct nonproscribed trade.
The appearance in the last half of the nineteenth century and first decades of the twentieth of sea mines, surface and submarine torpedo-attack craft, long-range rifled guns with exploding projectiles, and eventually aircraft meant that the traditional form of blockade-in close proximity to the adversary's coastline, where ships could be kept under surveillance and discouraged from departing their ports-could no longer be sustained.2 Thus maritime blockade evolved into long-range operations or blockade zones, and the rules that had been laid down for the conduct of blockade were for the most part ignored or rationalized away.
New technologies had required blockading states to move farther from the adversary's coastline, and at the same time they promoted the use of submarines and mines as instruments of blockade, because they were relatively immune to countermeasures by the blockaded party. In both the First and second World Wars the law-imposed requirements to visit and search ships, before attacking them, in order to determine whether they were carrying contraband and to provide for the safety of people on ships attempting to breach the blockade were massively violated.
A prescient Yale Law Journal article over a decade ago declared,
In the future blockade may become even more important as the need of a blockading state to stop every merchant ship grows more vital. The recent willingness of ostensibly neutral states to supply not simply technical know-how and materials for weapons construction, but also ready-for-use missiles and other decisive weapons, to the highest bidder portends such a future. As the negative consequences of allowing even one ship to pass uninspected grow more severe, blockading states will become more willing to use the new blockade forms [long-range blockade and blockade zones] at the expense of neutral interests.3
What the writer could not have foreseen happened on 11 September 2001events that changed the world, and in ways not yet fully comprehended. What was extraordinary about the events on that date was that a nonstate entity had succeeded in conducting a coordinated attack against a sovereign state on its home territory with a hitherto unappreciated weapon of mass destruction, a fully fueled airliner. Historically, weapons of mass destruction (WMD)-such as nuclear, chemical, radiological, and biological weapons-have been under the strict control of sovereign states, their manufacture, storage, and use carefully constrained physically by security measures and strategically by deterrence and international law. The message conveyed on 11 September was that henceforth weapons of mass destruction could be controlled, distributed, and perhaps used by nonstate entities or even individuals. …