It’s nice that we have a de facto Mexican heritage day (May 5 or Cinco de Mayo) to go along with the Irish heritage day of St Patrick’s day, but if I’m to have any pretensions to lecture on global awareness, I thought I had better look up the background at some point.
To my surprise Cinco de Mayo is a commemoration of a victory over an occupying French army who had come in when Mexico defaulted on their loans. Specifically el Cinco de Mayo remembers the Battle of Puebla on May 5, 1862.
Who’s to blame? Now that’s the interesting part. Everyone agrees that the French did the invasion, but different articles identify different co-conspirators. We have

• Spain and Britain who sent in forces along with the France.
• Conservative Mexicans who didn’t like the current administration (President Benito Juárez may have been too indigenous) and invited the French government to intervene.
• The United States because Mexico went into debt after the Mexican-American war two decades earlier. It should be noted that the Union government and later US government SUPPORTED the native Mexican government – partly so that the Confederates wouldn’t have French support and probably also because of the Monroe Doctrine.

It reminds me of the classic adage that “all politics are local.”
Whoever gets the blame for this episode, I’m glad Cinco de Mayo is one of the times the U.S. and Mexico DID work together.
The stories are
http://en.wikipedia.org/wiki/Cinco_de_mayo
http://en.wikipedia.org/wiki/Battle_of_Puebla
http://en.wikipedia.org/wiki/French_intervention_in_Mexico
http://www.pbs.org/kpbs/theborder/history/timeline/10.html
http://historicaltextarchive.com/sections.php?op=viewarticle&artid=747