"According to NSA documents - classified top secret... some senior officials in Washington wanted above all to protect Israel from embarrassment. "Captain Vineyard had mentioned during this conversation," wrote Tordella, "that consideration was then being given by some unnamed Washington authorities to sink[ing] the Liberty in order that newspaper men would be unable to photograph her and thus inflame public opinion against the Israelis... ""
January 1, 1970
https://en.wikiquote.org/wiki/USS_Liberty_incident