#OnThisDay (yesterday, actually, but I don't tweet on Rosh Hashanah): Sept. 20, 1940: Genevieve Grotjan, mathematician in US Army's Signal Intelligence Service, makes crucial break in Japan's Purple diplomatic cipher: #War_of_Shadows @sheeraf@SpitfireFilly@ShiraOvide
Gene Grotjan was 26. She'd entered civil service b/c she hadn't been able to get a college teaching job, apparently b/c colleges wouldn't hire women.
The only law always followed in war is the Law of Unintended Consequences. Grotjan's rejection by universities led to her career in codebreaking - and to the discovery that allowed U.S. to read Japan's most secret diplomatic cipher. @sarahposner@danephron
In sweltering heat of the Munitions Building - predecessor to the Pentagon - Genevieve Grotjan studied Purple messages and realized they'd been put through a triple scrambler similar to German Enigma. #War_of_Shadows
It was one week before German, Italy, Japan signed Tripartate Pact binding them to mutual defense. Negotiations likely increased flow of Japanese diplomatic traffic, helping breakthrough.
Under master codebreaker William Friedman, Signal Intelligence Service in Washington had broken Japan's earlier Red cipher. But in early 1939, Japan switched to Purple machine. Friedman's codebreakers then launched effort to break Purple.
Three weeks after Grotjan's insight, team under Lt. Leo Rosen builds ersatz Purple Machine. Japanese are using only few hundred of countless possible settings for Purple.
As usual, the encryption is no better than the care people take in using it. Taking off from Genevieve Grotjan's stroke of genius, Friedman's team rapidly finds settings that Japanese use on Purple cipher machine.
Big fear is that War Secretary Henry Stimson will shut down operation. Years earlier, as Herbert Hoover's Sect of State, Stimson shut U.S. codebreaking, famously explaining, "Gentlemen don't read other's mail."
In 1940, though, Stimson - a Republican - has joined FDR's cabinet to help prepare for likely war. He likes the break of Purple. "What you do in war & what you do in peace are two entirely different things," Stimson will explain. @natsecHeather@artgoldhammer@ArielliNir
Thanks to Genevieve Grotjan, now FDR, Stimson & US military leaders can read Japanese diplomatic messages. But even decoded messages hold unclear warnings. Missing their meaning can have disastrous consequences. @dovalfon@NimrodNovik@calder_walton
US Sect of State Blinken saying that Israeli settlements in West Bank are "inconsistent with international law" is indeed important symbolically.
However, news items on this are mixing up the history of US policy on settlement illegality.
The Carter administration wasn't the first to label settlements illegal. That was US policy from 1967 onward. As seen in this cable of 8 April 1968 from the State Dept to the US embassy in Israel:
In 1976, the US ambassador to the UN, William Scranton, said in the Security Council that settlements violate IV Geneva and are illegal.
This @washingtonpost deep dive, like others, confirms Hamas deliberately provoked the invasion of Gaza, knowing that it was sacrificing countless Palestinian lives.
@washingtonpost The deaths of thousands in Gaza are as much part of Hamas's plan as the deaths of Israeli civilians on October 7.
The goal was to set off greater conflict, in the name of achieving Hamas's goal - both cruel and utterly without a chance of success - of destroying Israel.
@washingtonpost Hamas fought its way through the thin line of Israeli soldiers on the border in order to reach civilians - to kill, take hostages, and commit other atrocities.
Churchill's knowledge of Nazi mass murder in occupied Soviet territory came from Bletchley Park, where master codebreaker John Tiltman's team had cracked the cipher used by special German police units to report how many people they'd shot. (2) @calder_walton@spyhistory
Like this message from 18 July 1941, in which a Nazi police regiment reports that it had shot "1153 Jewish plunderers."
The reports were coldly bureaucratic.
אז @OferShelah אומר שלמפלגה חייבת להיות דרך. כלומר, מדיניות, תוכניות. אזי אני שואל, מה תוכניתו בעניין:
⦿ חידוש חתירה להסכם שתי מדינות
⦿ הפסקת מימון להתנחלויות והרחבתן
⦿ העלאת מסים על העשירים, כדי לממן -
⦿ כיתות קטנות, שכר נדיב למורים... @dahliasc@AnshelPfeffer@chaimlevinson
עוד שאלות ל- @OferShelah - מה אתה מציע על מנת
⦿ לרפא את מערכת הבריאות המורעבת
⦿ לאפשר לצעירים להשיג דיור
⦿ להחזיר מקומות עבודה בעקבות משבר הקורונה
⦿ להוזיל ולהרחיב תחבורה ציבורית במקום תלות ברכב פרטי...
ועוד שאלות ל- @OferShelah - מה אתה מציע על מנת
⦿ לסגור את הפערים העדתיים בהשכלה ובהכנסה שלמרות ההכחשות עוד קיימים
⦿ להבטיח שוויון מלא לאזרחים ערביים
⦿ לשנות את פני החינוך החרדי...
So @OferShelah says a party actually needs a program. Totally true. Therefore asking for his program on:
⦿ Achieving 2-state outcome
⦿ Settlements, & defunding them
⦿ Raising taxes on wealthy, to pay for -
⦿ Smaller classes, better-paid teachers...
More questions to @OferShelah - what do you propose to
⦿ Heal underfunded health system
⦿ Make it possible for young people to afford apartments
⦿ Restore jobs lost to pandemic
⦿ Make public transport affordable, efficient, replace cars...
And more questions to @OferShelah - what do you propose to
⦿ Deal with long-lasting effects of Ashkenazi-Mizrahi wealth & education gap
⦿ Ensure full equality for Arab citizens - incl place in govt for their representatives
⦿ Transform haredi education...