On November 14, 1940, the German Luftwaffe launched a massive bombing attack on Coventry.  Over 60,000 buildings were destroyed.

http://www.historiccoventry.co.uk/blitz/stats.php

It has long been rumored that Winston Churchill knew about the bombing in advance because British Intelligence had broken the German code.  There were over 300,000 people living in Coventry, yet there was no attempt to beef up defense or even evacuate the city.  Some people believe that Winston Church allowed this to happen because he felt that it was more important to not let Germany know Britain had broken their code.

The Battle of Midway was won in large part because Navy cryptographers had broken parts of the Japanese Naval code.  They alerted Admiral Nimitz of the plan by Japan to invade Midway.  The U.S. victory at Midway turned the tide in the Pacific War.

These are two examples of why signals intelligence is so important.  When I was attached to the NSA we were reminded that the most vital information to protect is the information “what we know about the other side.”  Everyone knows that both sides are spying on each other.  That is not news.  Both the Germany and the Japan knew our troops were listening to them.  What they did not know was what we learned from this intelligence.  They did not know that their codes have been compromised.

This is why it really matters that one of the e-mails sent on a private server belonging to Hillary Clinton contained SI or signals intelligence.  If Hillary allowed our enemies to learn what we know about them that would do incalculable damage to national security.  That is why most people charged with failure to protect signals intelligence end up in jail.  This is not a minor problem.  It is not a partisan witch hunt.  It is far more important than that.  Just ask the people who were in Coventry in November 1949.

TDM