SPY (from " to spy " or " espy"; O. Fr. espie, espier, to spy, watch; cf. Ger. spa'hen, Lat. specere, to look; the Fr. term "espionage " is of course from the same source) , in war a person who, disguised or without bearing the distinguishing marks of belligerent forces, mixes with the enemy for the purpose of obtaining information useful to the army he is serving. As by the law of war a spy is liable, if caught, to the penalty of death, the Hague " Regulations respecting the Laws and Customs of War on Land " are very precise on the subject. A soldier not wearing a disguise is not a spy, though he may be found within the zone of the hostile army and though his object may be to obtain information; nor are soldiers or civilians spies who cross enemy lines openly carrying messages. This applies even to persons sent in balloons for the purpose of carrying despatches. In short, it is essential to the character of a spy that he should act clandestinely or on false pretences, that he should be caught within the zone of operations of the hostile belligerent forces, and that his object should be to obtain information for use against them (art. 29). The regulations also provide that he cannot be " punished " without previous trial (art. 30). Nor can he be treated as a spy if he is captured after he has rejoined his army. He must then be treated as an ordinary prisoner of war (art. 31). (T. BA.)
The term " spy " is applied also to those who in time of peace secretly endeavour to obtain information concerning the forces, armaments, fortifications or defences of a country for the purpose of supplying it to another country. Every country has always endeavoured to guard jealously its military and naval secrets, and with this object denies admittance to fortified places or arsenals to those who cannot produce the proper credentials. Notwithstanding the utmost precautions, it is impossible to prevent some amount of leakage to countries which are prepared to pay for information otherwise unobtainable. Consequently, most countries have legislation dealing with " spying " in time of peace. In the United Kingdom, the Official Secrets Act 1889 makes it a misdemeanour wrongfully to obtain information as to any fortress, dockyard, office, etc., of his majesty, or, having such information or any information relating to the naval or military affairs of his majesty, to communicate the same to any person to whom it ought not in the interest of the state to be communicated at the time. If the information is communicated, or intended or attempted to be communicated, to any foreign state, the offence becomes a felony. In Germany an imperial law of 1893 deals similarly with such an offence.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)