And to those nations like ours that enjoy relative plenty, we say we can no longer afford indifference to the suffering outside our borders; nor can we consume the world's resources without regard to effect. For the world has changed, and we must change with it.

As president of the United States, I don't bluff.

Here's the truth: even if countries like the United States curb our emissions, if growing countries like India - with soaring energy needs - don't also embrace cleaner fuels, then we don't stand a chance against climate change.

I look forward to hosting Prime Minister Lee [Hsien Loong], whose friendship and partnership I appreciate very much and with whom I've worked throughout my administration. This will also be an opportunity for me to reciprocate the hospitality that the Prime Minister and the people of Singapore showed to me during my visit to Singapore for the APEC summit in 2009.

There's no doubt that probably at least once a week, maybe once a day, I said, "Ah, I should have done that better."

There is a theory that basically says that we can shred regulations and consumer protections and give more and more to the most, and somehow prosperity will trickle down. It hasn't worked. And I think that the fundamentals of the economy have to be measured by whether or not the middle class is getting a fair shake.

But at a time when our discourse has become so sharply polarized - at a time when we are far too eager to lay the blame for all that ails the world at the feet of those who think differently than we do - it's important for us to pause for a moment and make sure that we are talking with each other in a way that heals, not a way that wounds.