The Israeli diplomat, who did not identify himself, said officials in Tel Aviv anticipate a protracted crisis in neighbouring Egypt as the Brotherhood has no intention of giving up power without a fight.
"President Barack Obama's 'naivete' led him to engage in dialogue with the Muslim Brotherhood and paved the way for the downfall of Mubarak," the official was quoted by the Israel Radio as saying.
Mubarak's successor and Egypt's first elected President, Mohammed Morsi, a former Brotherhood member, was toppled by the powerful military last week and since has been kept in detention along with some senior aides of his Islamist party.
General Abdel Fattah al-Sisi, the commander in chief of the Egyptian armed forces, realised what was at stake and took it upon himself to "rescue Egypt" from Islamist rule, the source added.
US law mandates that foreign aid be cut off to a country in which the military removes a democratically elected government. US provides USD 1 billion in annual aid to Egypt.
However, the White House has refused to label the military ouster of Egypt's President a coup and said there would be no immediate cut in the aid.
Obama and his top aides have denounced the ouster of the democratically elected Morsi but have been careful to avoid calling for him to be reinstated, prompting speculation that the United States tacitly supported his ouster.
