A huge explosion ripped through the United Nations' headquarters in downtown Baghdad (search) Tuesday, killing at least 15 people including the U.N. Special Representative in Iraq, Sergio Vieira de Mello.

We'll get reaction to the attack from Bernard Kerik, senior U.S. law enforcement official in Baghdad.

Plus, should the U.S. be responsible for beefing up security of soft targets in Iraq? Or does is it time for the international community to step up? We’ll ask retired U.S. Army Col. David Hunt, FNC military analyst, and retired U.S. Navy SEAL Martin Strong.

And, while it's not clear yet who is responsible for today's bombing in Baghdad, the message was clear: “Get out of Iraq.” Is it time to pick up and leave? We’ll ask Robert Baer, former CIA officer and author of See No Evil.

First it was the U.N. compound in Iraq and then hours later, over 20 are killed in a bus bombing in Jerusalem. We’ll get reaction from Dan Gillerman, Israeli ambassador to the United Nations.

What does the Bush administration have to do now to keep the rebuilding process moving forward? Former House Speaker Newt Gingrich, author of Gettysburg, weighs in.

Did Tuesday’s deadly blast impact on the U.S. stock market? We’ll ask Sarat Sethi, principal and portfolio manager at Douglas C. Lane & Associates; Paul Rabbitt, president of Rabbitt Analytics; Donald Straszheim, president of Straszheim Global Advisors, and Bob Hormats, vice chairman of Goldman Sachs.

Plus, Harley Davidson is turning 100. We’ll ask CEO Jeffery Bleustein how he is keeping his company in hog heaven, on tonight’s edition of Your World with Cavuto.

About Your World...

More than just facts and figures, Your World with Cavuto gets to the heart of the matter with in-depth analysis from our FOX Business News All-Stars:

Terry Keenan, host of Cashin' In
Brenda Buttner, host of Bulls & Bears
David Asman, host of Forbes on Fox