In March 1915 Bottomley began a regular weekly column for the "Sunday Pictorial". On 4 May, after the sinking of the "Lusitania", he used this column to label the Germans as "unnatural freaks", and called for their extermination. Britain's war effort, he maintained, was being hampered by squeamish politicians; he reserved particular venom for the Labour Party leaders, Keir Hardie and Ramsay MacDonald, who opposed the war, and demanded they be tried for high treason. Macdonald's riposte—to label Bottomley "a man of doubtful parentage who had lived all his life on the threshold of jail"—backfired when the latter published Macdonald's birth certificate which showed that the Labour leader was himself illegitimate. Bottomley also criticized the neutrality policy of the United States, arguing the USA was using the war to increase its economic power at the expense of the European powers. Bottomley launched a series of attacks on President Woodrow Wilson that lasted until the US entered the war in 1917.