America is in its darkest hour -- again. It happens every four years when the Democrats take center stage for their national convention. In 2004, we heard that we were in the midst of another Great Depression. For the last week, we've heard more economic doom and gloom. It must have been disappointing news to Dems to read on Thursday that the U.S. economy grew 3.3 percent in the second quarter. It's hard to turn those numbers into a recession, much less a depression, but Barack Obama and his compatriots certainly tried.

But if the Democrats see disaster on every domestic front, they seem oblivious to the real threats to the United States. There was barely a word about terrorism, and scant mention of national security during the weeklong gabfest. Wednesday's proceedings, which convention organizers had promised was going to be devoted to national security themes, barely touched on the issue. That is unless you think Steven Spielberg and Tom Hanks are experts on national security. The Spielberg film tribute to American soldiers, narrated by Hanks, was an interesting take on America's mission in Iraq. Apparently we sent soldiers there not to liberate the country and take down a brutal dictator but to see how many young Americans we could maim or send home in caskets.

The most glaring omission, however, was in Sen. Joe Biden's speech. Barack Obama picked Biden as his running mate largely because Biden's strength on foreign policy issues balanced Obama's obvious weakness in this arena. Biden, the chairman of the Senate Foreign Relations Committee, spent most of his time spinning folksy stories about his working-class background and making digs at his "friend" John McCain. Biden devoted less than a paragraph of his long, rambling speech to national security and foreign policy.

He was quick to blame the Bush administration for failing "to face the biggest forces shaping this century: the emergence of Russia, China, and India as great powers ... and the emergence of fundamentalism in Afghanistan and Pakistan, the real central front in the war on terror." But he offered no inkling of what Barack Obama and he would do differently.

And when Obama finally took the stage at Invesco Field, he tried to sound tough on national defense largely by attacking his opponent. "John McCain likes to say that he'll follow bin Laden to the Gates of Hell -- but he won't even go to the cave where he lives," Obama jabbed. Aside from the bad taste of questioning war hero John McCain's courage, Obama raised again the possibility that he will bomb Pakistan if he is elected. A year ago, Obama said that he'd be willing to attack targets in Pakistan without the approval of the Pakistan government, "if we have actionable intelligence about high-value terrorist targets." Thursday night's version was a little less specific but no less bellicose, and once again raised questions about whether Obama is ready to be president.

Of course, Obama tried to reassure voters that he and the Democrats are strong on national security. "We are the party of Roosevelt. We are the party of Kennedy. So don't tell me that Democrats won't defend this country. Don't tell me that Democrats won't keep us safe," he roared to an approving crowd. But Obama is no Roosevelt. And not even an outdoor sports arena reprise of JFK's 1960 acceptance speech will fool anyone into believing that Obama is a Democrat hawk like Kennedy.

Democrats had a week to describe how Barack Obama would step into the role of commander in chief come January. They failed to do so. Now it's up to American voters to decide whether they're willing to make a leap of faith that Obama's up to the job.