Background on the inversion mania

From the Tax Analysts blog, which I believe is open to the public. Key takeaway:

Here is the ultimate irony in the story: Investment bankers hired by a foreign multinational confronting acquisition by a U.S. corporation alerted the administration, the politicians, and the country to the imperatives of “economic patriotism.”

It was all part of AstraZeneca's defense against a hostile takeover.