You can read a news article here, which has this headline:
Andrew Morton traces the Nazi links of the Duke and Duchess of Windsor
This quote is from the news article:
Lurking behind these shenanigans and the object of the book is their closeness to Nazi Germany. So close the Duchess, then Mrs Simpson, allegedly had an affair with Joachim von Ribbentrop, the reason for the title 17 Carnations – one for every night of their lovemaking; Morton admits they may have been roses. This was all grist to Hitler’s plan to overcome Britain and reinstate the Duke as puppet King, and Wallis as Queen. “She would have made a wonderful Queen,” he murmured.
Later, von Ribbentrop’s crafty plot for kidnapping the couple, offering as bait up to 50 million Swiss dollars ($200 million today) and a castle in Spain, came to naught. A seething Prime Minister Winston Churchill sent them packing to the Bahamas.