ISRAEL - The rapid collapse of the Afghan government and its US-backed security forces shows how the American attempt to instill in Afghans a liberal worldview in the space of 20 years was politically and culturally impossible and how misguided that approach was. But the more fundamental problem is that the US decision to leave Afghanistan is part of an American strategy to reduce its role as an international superpower, especially in the Middle East. This may encourage radical Islamic elements such as Iran, al-Qaeda, ISIS, and elements of the Muslim Brotherhood, including Hamas, to challenge the US and its allies, including Israel. The essential lesson for Israel is that with all the importance of Israel's strategic partnership with the US, Israel must recognize the limitations of a superpower's backing and adhere closely to the principle that Israel will defend itself on its own. This is a relevant lesson in the Iranian context when the Americans project hesitation in response to Tehran's many provocations.