Here is an excellent article that explains clearly why the strike was necessary. The article appears in the newsmagazine called F, published by the Art Institute of Chicago, a venerable institution.
Mayor Rahm said it was a “strike of choice.”
In this sense, he was right. The teachers could have just kept on teaching under dismal conditions for students, or they could strike and demand better conditions in the classrooms and schools for the students and teachers.
He chose to defend the status quo. The teachers said “no” to the status quo. They said the status quo was intolerable. And that is why they went on strike.
Diane Ravitch's blog 
“We’ve been micromanaged into doing things that we know are harmful for our children,” explained Chicago Teachers Union president Karen Lewis in an interview with Amy Goodman on Democracy Now. “It has been a real victory to finally stand up and say, ‘This is not a good way of doing school, just because somebody in an air-conditioned building with a spreadsheet thinks it is a good way of doing it.’”
I admire Karen Lewis’ courage and strong leadership. Her articulate message should embolden teacher union leaders everywhere.
Last I checked, Chicago was in Illinois and subject to US treaties. The experts cited for the subject article make no reference to human rights treaties ratified by the US in their work:
Handbook of Social Justice in Education, William C Ayers, Therese Quinn
Looks to me like a major problem if President Obama’s former chief of staff isn’t on course to implement applicable treaty provisions in Chicago schools. Perhaps the UN won’t be as impressed with the President’s efforts as Secretary Clinton believes.
Duncan and Obama now are trying to make nice to the teachers:
http://www.washingtonpost.com/local/education/arne-duncan-tries-to-smooth-relations-with-teachers/2012/10/02/04881100-0ccc-11e2-a310-2363842b7057_story.html?wpisrc=nl_headlines
Read the first comment following the article. I stopped after the first few sentences. I can’t tolerate ignorance and UGs (unsubstantiated generalizations) any more. Have we teachers ever said that poor teachers should continue teaching? Arg!