BBC News
with David Legge
奥巴马发表中东政策演讲回应北非等地动荡局势
President Obama has outlined US policy towards the Middle East in the wake of the momentous events in the region in the past few months. He spoke of peoples who'd risen up and brought about change through non-violence. From Washington, Paul Adams reports.
This was a speech of necessarily broad scope, an opportunity for the president to draw what he believes are the lessons of six months of turmoil in the Arab world and to say how the United States is responding.
"We have the chance to show that America values the dignity of the street vendor in Tunisia more than the raw power of the dictator. There must be no doubt that the United States of America welcomes change that advances self-determination and opportunity."
There were pledges of significant international economic support for countries undergoing democratic change, notably Egypt and Tunisia, and a stern warning to Syria's President Bashar al-Assad, similar in language and tone to the one delivered to Egypt's Hosni Mubarak just before the White House cut him adrift.
President Obama devoted a significant portion of his speech to the Israeli-Palestinian conflict. He said any Palestinian state should be based on the 1967 borders. Correspondents say that appears to meet a key Palestinian demand and to mark a shift in US policy. Wyre Davies is in Jerusalem.