This was before he massively supported the State of Israel, of course.
From The New York Times:
“The so-called Stern gang” of Zionist terrorists tried to assassinate President Truman by letter bomb in 1947, according to a new biography written by Mr. Truman’s daughter.
Mrs. Margaret Truman Daniel writes that “a number of cream colored envelopes, about eight by six inches, arrived in the White House, addressed to the President and various members of the staff.” They were found to contain “powdered gelignite, a pencil battery and a detonator rigged to explode the gelignite when the envelope was opened.”
But the White House mail room, alert to the danger of postal bombs, discovered the letters and had them defused by Secret Service bomb experts, Mrs. Daniel writes in her book, “Harry S. Truman,” which is being published by William Morrow & Co.
As far as could be immediately determined, Mrs. Daniel is the first member of the Truman White House circle to confirm that the letter-bombs arrived, although the report also appeared in a 1949 book, “‘Dear Mr. President . . .’ The Story of Fifty Years in the White House Mail Room,” by Ira R. T. Smith, with the collaboration of Joe Alex Morris.
In another note, written in March, 1948, Mr. Truman complained that “The State Dept. pulled the rug from under me” with a statement contrary to his own policy on the Palestine question. In the previous summer, Mrs. Daniel writes, the Stern gang, an ultramilitant zionist group, “tried to assassinate Dad by mail” by sending the cream-colored envelopes. She says that each contained a second, smaller envelope marked “Private and Confidential”—which in turn contained the explosive components.
She writes that the White House staff was alert to the danger because similar letters had been mailed to high officials in Britain and intercepted.
Mrs. Daniel does not say why the bombs were attributed to the Stern gang, but Mr. Smith, in his book, reported that the gang had claimed responsibility for having sent the letters to England from its “branch in Europe” and notes that, they were postmarked from Italy.
The gang was named for its original leader, Abraham Stern, who had been killed by the British in 1942.
According to press reports in 1947, the Stern gang’s claim was made in Jerusalem, and similar explosive envelopes had been found previously in Palestine.
The gang’s spokesman was quoted as having said shortly before that some of its major figures “might have left the country,” but he did not say why, although the implication seemed to be that they might have been involved in mailing the letters.
In Italy, the police said in June of 1947 that they had no clues as to who had sent the bombs, however.
I don’t intend to infer anything.