The White House said on Monday the defection of Syria’s prime minister showed that President Bashar Assad’s government was “crumbling from within,”repeating its call for him to step aside and end the violence gripping the country. “This is a sign that Assad’s grip on power is loosening. If he cannot maintain cohesion within his own inner circle, it reflects on his inability to maintain any following among the Syrian people,” White House spokesman Jay Carney told a news briefing here.