Reports that President Donald Trump's son-in-law Jared Kushner was trying to establish a secret line of communication between the Trump transition team and Russian government officials have raised concerns among U.S. defense and intelligence experts. It remains unclear what his intent may have been, but Kushner is reportedly at the center of an investigation into possible ties between the Trump campaign and Moscow.
The White House has neither confirmed nor denied that Kushner made such an effort, but some of the president's allies said the 36-year-old businessman would have been doing nothing wrong by trying to forge better relations with the Kremlin before Trump assumed office.
White House counselor Kellyanne Conway told Fox News that back-channel communications were "the regular course of business."
She's not entirely wrong.
It would be unusual to try to establish such a channel before the start of an administration, and it is unclear what its aim would have been in dealing with Russia. But throughout recent history, the United States and other nations have used private communications and secret negotiations to reach consensus and forge deals.
According to Safire's Political Dictionary, a back channel is "a seemingly unofficial but direct method of high-level communication, bypassing the usual routes of messages through bureaucracies." The communication is typically between adversaries, sensitive in nature and conducted through an intermediary.
Back channels have been used by various governments to negotiate peace deals, placate foes, secure the release of prisoners and save face.
Here are some notable examples:
