Soviet soldiers died or went into prison camps. Some of the Red
Army commanders responsible for defeats on the Eastern Front were
arrested and shot in the fall of 1941—the final casualties of the
Tukhachevskiy affair.- U –
ULTRA.The British code name “Ultra” was given to intelligence de-
rived from breaking the codes of Germany’s Enigma machine. Sen-
sitive top secret information decoded from the intercepted messages
was referred to as “Ultra top secret.” With the exception of the atom
bomb, Ultra was the greatest secret of the war: it provided the West-
ern Allies with critical naval, air, and army information. Ultra intelli-
gence also included detailed information on the German military’s
order of battle and military planning on the Eastern Front. The prob-
lem for the British government was how to pass this material to the
Soviet Union without revealing its source.
The British government passed Ultra material to Moscow through
liaison between the two countries’ intelligence services without re-
vealing that it came from signals intelligence. (American and British
generals were misinformed as well; they were told that the material
with the fictional code name “Boniface” came from a spy ring inside
Germany.) The British may also have passed diluted versions of the
material to Moscow through a spy ring operating in Switzerland.
None of this saved the Ultra secret from Moscow: Soviet agent John
Carincrossprovided his Soviet case officers with thousands of raw
Ultra messages during the war. The Soviet military considered this
material “very valuable” in preparing to counter the last German
strategic offensive of the war at Kursk in 1943. Carincross’s treach-
ery also allowed Moscow to check the material they were receiving
from London and to understand British capabilities to break codes,
including their own. The British and American public found out
about the Ultra secret 30 years after the Soviets did.UNSHLIKHT, JOSEPH STANISLAVOVICH (1879–1938). Born
into a middle-class Polish Jewish family, Unshlikht joined the under-272 •ULTRA06-313 P-Z.qxd 7/27/06 7:57 AM Page 272