Among military stratagems the older writers used to include every kind of deception practised by generals in war, not only against the enemy, but against their own troops; as, for instance, devices for preventing or suppressing a mutiny, for stopping the spread of a panic, or for encouraging them with false news before or during an engagement.
But in modern use the term stratagem has almost exclusive reference to artifices of deception practised against an enemy; and the greater interest that attaches to the latter kind of guile justifies the narrowed denotation of the word. No one, for instance, would now regard as a stratagem the clever behaviour of that Thracian general Cosingas, who, acting also as priest to his forces, brought them back to obedience by the report he artfully propagated that certain long ladders which he had caused to be made and fastened together were intended to enable him to climb to heaven, there to complain to Juno of their misconduct. The false pretence that is involved in a stratagem is addressed to the leaders of a hostile force, in order that their fear or confidence, unduly raised by it, may be played upon to the advantage of their more artful opponents. In the consideration, therefore, of military stratagems, or ruses de guerre, it is best to conform entirely to the more restricted sense in which they are understood in modern parlance.
The following stratagem is a good one to start with. During the Franco-German War of 1870, twenty-five franc-tireurs clothed themselves in Prussian uniform, and by the help of that disguise killed several Prussians at Sennegy near Troyes; and the deed was made a subject of open boast in a French journal.[164] Was the boast a justifiable or a shameful one?
Distinctly justifiable, if at least Grotius, the father of our international law, is of any authority. The reasoning of Grotius runs in this wise. There is a distinction between conventional signs that are established by the general consent of all the world and those which are only established by particular societies or by individuals; deception directed against the former involves the violation of a mutual obligation, and is therefore unlawful, whereas that against the latter is lawful, because it involves no such violation. Therefore, whilst it is wrong to deceive an enemy by words or signs which by general consent are universally understood in a given sense, it is not wrong to overcome an enemy by conduct which involves no violation of a generally recognised and universally binding custom. Under conduct of the latter type fall such acts as a simulated flight, or the use of an enemy’s arms, his standards, uniform, or sails. A flight is not an instituted sign of fear, nor have the arms or colours of a particular country any universally established meaning.[165]
And in spite of the sound of sophistry that accompanies this reasoning, the teaching of international law has not substantially swerved on this point from the direction given to it by Grotius. In Cicero’s opinion, although both force and fraud were resources most unworthy of rational humanity, the one pertaining rather to the nature of the lion and the other to that of the fox, fraud was an expedient deserving of more hatred than the other.[166] But the teaching of later times has tended to overlook this distinction. Bynkershoek, that celebrated Dutch jurist who advocated the use of poison as one of the fair modes of employing force, declares it to be a matter of perfect indifference whether stratagem or open force be employed against an enemy, provided perfidy be absent from the former. And Bluntschli, who is the German publicist of greatest authority in our own day, expressly includes among the lawful stratagems of war the use of an enemy’s uniform or flag.[167]
If, then, we test the received military theory by some actual experience, the following episodes of history must challenge rather our admiration than our blame, and stand justified by the most advanced theories of modern international law.
Cimon, the Athenian admiral, having captured some Persian ships, made his own men step into them and dress themselves in the clothes of the Persians; and then, when the ships reached Cyprus, and the inhabitants of that island came out joyfully to welcome their friends, they were of course more easily defeated by their enemies.[168]
Aristomachus, having taken some Cardian ships, placed his own rowers in them and towed his own ships behind them, as if they were being conducted in triumph. When the Cardians came out to greet their supposed victorious crews, Aristomachus and his men fell upon them and succeeded in committing great carnage.[169]
Modern history supplies analogous cases. In September 1800 an English crew attacked two ships that lay at anchor at Barcelona, by forcing a Swedish vessel to take on board some English officers, soldiers, and sailors, and so obtaining a means of approach that was otherwise impossible.[170] And English naval historians tell with pride, rather than with shame, how in 1798 two English ships, the ‘Sibylle’ and the ‘Fox,’ by sailing under false colours captured three Spanish gunboats in Manilla Roads. When the Spanish guard-boat was sent to inquire what the ships were, the pilot of the ‘Fox’ replied that they belonged to the French squadron, and that they wished to put into Manilla, for the recovery of the crews from sickness. The English Captain Cooke was introduced under the French name of Latour; and a conversation ensued in which the ceremony of wishing success to the united exertions of the Spaniards and French against the English was not forgotten. Two Spanish boats having then come to visit the vessels, their crews were quickly handed below; and a party of British sailors having changed clothes with them and got into their boat, advanced to the gunboats, which they captured without pulling a trigger.[171]
On another occasion the same ‘Sibylle,’ which had been taken from the French by Romney in 1794, captured a large French vessel that lay at anchor, by standing in under French colours, and only hoisting her real ones when within a cable’s length of her prize;[172] the only limit to such a stratagem on the sea being the necessity for a ship to hoist her real flag before proceeding to actual hostilities. A state of war must surely play strange tricks with our minds to make it possible for us to approve such infamous actions as those quoted. There can be no greater proof of the utter demoralisation it causes than that such devices should have ever come to be thought honourable; and that no scruples should have ever intervened against the prostitution of a country’s flag, the symbol of her independence, her nationality, and her pride, to the shame of open falsehood. Antiquaries dispute the correctness of the statement of Polyænus that Artemisia, the Queen of Caria and ally of Xerxes against Greece, hoisted Persian colours when in pursuit of Greek ships, but a Greek flag to prevent Greek ships from pursuing herself, because they say that flags were not then in use; but undoubtedly the custom is a very old one on the seas of having a number of different flags on board a ship, for the purpose either of more easily capturing a weaker or of more easily escaping from a stronger vessel than herself. The French, for instance, in 1337 plundered and burnt Portsmouth, after having been suffered to land under the cover of English banners.[173] Not only the vessels of pirates and privateers, but the war vessels of the State, learned to sail under colours that belied their nationality.[174] The only limit to the stratagem of the false flag (to which international custom gradually came to give the force of law) came to be the necessity of hoisting the real flag before proceeding to fire, a limitation that was not of much moment after the successful deception had brought a defenceless merchant vessel within the reach of easy capture. And with regard to ships of war, the cannon-shot by which one vessel replied to the challenge of its suspected nationality by the other came to be equivalent to the captain’s word of honour that the flag which floated above the cannon he fired represented the nationality of which it professed to be the symbol. The flag itself might tell a lie, therefore the cannon-shot oath must redeem it from suspicion. Such are the extraordinary ideas of honour and morality that the system of universal fear, distrust, and hostility, by many thought to be so surpassingly glorious, has caused to become prevalent upon the ocean.