The "silent minute" was created to remember the war dead, not for any psychic reasons to protect Britain. And it didn't originate with Churchill.
If it had originated in WWII, we'd have to note that it was something of a bust. Over 30,000 Londoners were killed just in the blitz of 1940-41:
The concept of Remembrance Silence is a traditional token of respect for the dead. It is most famously associated with the Two Minutes' Silence observed each year at 11 a.m. on 11 November — Armistice Day — a tradition inaugurated by King George V in 1919 to commemorate the first anniversary of the end of hostilities on the Western Front.
The widespread observance of a ceremony of silence at 9 p.m. in New Zealand actually dates from the Second World War and the story of its origin is a remarkable one. It begins not during the Second World War, however, but the First World War.
In early December 1917, in the mountains around Jerusalem, two British Army officers were discussing the war and its probable aftermath on the eve of a battle. One of them, in a premonition of his death, requested his fellow officer to remember him and the millions of others who would die during the War: "Lend us a moment of it every day and through your silence is greater than you know".
The following day the speaker, as he had foretold, was killed. His companion, Major W. Tudor Pole, never forgot his comrade’s last request and at the outbreak of the Second World War campaigned tirelessly to implement a daily observance of silent prayer.http://www.rsa.org.nz/remem/rsa_hist_ceremony.html BTW, the name was Wellesley Tudor-Pole....though on several pSykiK sites, I found it given as "Wesley." Figures.