http://www.signature-editions.com/index.php/books/single_title/the_back_channels

What exactly are back channels, and when is it OK to use them?

Donald Trump came back from his first overseas presidential trip to yet another political firestorm. This one's focused on his son-in-law and special adviser, Jared Kushner.

Kushner is widely reported to have become a focus of the FBI investigation into alleged ties between the Trump campaign and the Kremlin.

Leaked intercepts of messages from Russian ambassador Sergei Kislyak allegedly state that after the US election in November, Kushner asked if he could set up a secret channel of communication to the Kremlin using secure Russian technology.

President Trump has tweeted that all these recent leaks are just fake news.

But nobody else has denied it. Homeland Security Secretary John Kelly and National Security Adviser H.R. McMaster only say there's nothing wrong with back channels.

So what exactly is a back channel, and when is it appropriate?

“It essentially means creating a channel of communication with another government or with representatives of another government, that is discreet, that doesn’t go through the official channels of diplomatic cables, of using ambassadors and more formal methods of communicating," says Peter Kornbluh, who co-wrote the book "Back Channel To Cuba: the Hidden History of Negotiations between Washington and Havana."

https://www.pri.org/stories/2017-05-29/what-exactly-are-back-channels-and-when-it-ok-use-them