It seems the US (amongst others) is determined to send a hard line message to Iran's leaders.

But Iran doesn't look like it will be relinquishing anything soon.

So Obama's speech should get you wondering about where all this is going:

BBC News: "Iran's leaders should know that I do not have a policy of containment - I have a policy to prevent Iran from obtaining a nuclear weapon," Mr Obama told the annual American-Israel Public Affairs Committee (Aipac) policy conference in Washington. "And as I've made clear time and again during the course of my presidency, I will not hesitate to use force when it is necessary to defend the United States and its interests."