Nearly 10 years after the attacks on Sept. 11, 2001, questions continue to be raised on security: How should Americans feel about the tens of billions of taxpayer dollars spent to beef up aviation security?

And what about all those hours we've spent waiting on lines, taking off our shoes and surrendering our liquids and gels -- have they been worth it?

After the Christmas near-miss, when officials say a 23-year-old Nigerian man carrying explosives nearly succeeded in detonating himself on board a trans-Atlantic flight, many experts say Americans should be outraged.

Andrew Thomas from the Journal of Transportation Security says the government should be very disappointed in its actions and that "we need to hold these people accountable."

Many of the key recommendations of the 9/11 Commission to make the country safer still haven't been implemented.

For example, we still don't have widespread, reliable technology to check if passengers have explosives hidden in their underwear or inside their body.

Transportation Safety Administration screeners still only check 50 percent of the cargo that passenger planes carry in their holds. And the government still can't immediately check the names of all passengers against a single terrorist watchlist, even though technology expert Eddie Schwartz was able to cross-reference two lists of wanted criminals for us in about a half hour.

"You can certainly do that. It's not a difficult thing to do," said Schwartz from Netwitness Corporation, a security technology company.

Lee Hamilton, the former vice chairman of 9/11 commission who currently serves on the president's Homeland Security Advisory Council says that in his view, "Our government has not given the urgency to the task that it requires. I still sense a sort of business as usual attitude."

And so we ask: who is to blame?

Critics say it's a combination of a privacy advocates fighting full body scanners, airlines fighting increased security that would increase their costs, and a bureaucracy prone to infighting and waste.

For example, in 2004, the government spent nearly $30 million on so-called puffer machines, explosives-testing devices that didn't work.

Even though President Obama today called what happened on Christmas Day a "mix of human and systemic failures," the response from current and former government officials is that the system now in place is vastly better than it was pre-9/11.

Former Homeland Security Secretary Michael Chertoff said not to overlook the fact that "the efforts have forced [suspected terrorists] to ever more complicated methods of evasion, which means they are more likely to fail."

But even those who defend the current system say a lot more work needs to be done.

One former 9/11 commission member wondered how the government could possibly be satisfied after a plane nearly went down on Christmas? No one believes we will ever have perfect security, although everyone agrees what we have now is not good enough.