The delayed sentencing of former national security adviser Michael Flynn — for lying to investigators about “sensitive matters” discussed with the Russian ambassador to the United States during the Trump presidential transition — leaves unanswered questions about alleged collusion between Flynn and the Russians during the 2016 campaign.

It also evokes parallels with another former national security adviser, Richard Allen. Allen played a leading role in the Anna Chennault affair, a secret plan formed by Richard Nixon’s campaign to collude with the South Vietnamese government during the 1968 presidential campaign and sabotage Vietnam peace talks in Paris to ensure a Nixon victory.

The Chinese-born widow of a U.S. Air Force general, Chennault was the Nixon campaign’s conduit to the government in Saigon during the 1968 campaign through her friendship with Bui Diem, the South Vietnamese ambassador in Washington and Saigon’s representative at the peace talks.