WASHINGTON — Was Christmas Day 2009 the same kind of wake-up call for Barack Obama that Sept. 11, 2001, had been for George W. Bush?

The near-miss by a passenger flying into Detroit plotting to blow up an American airliner seems to have shocked this president as much as the attacks on the World Trade Center and the Pentagon did the last.

Both presidents had had plenty of warnings in the form of prior threats and even incidents. But both were caught off-guard: Bush reading to a classroom of youngsters; Obama on a family vacation in Hawaii.

Bush reacted with anger and a determination to punish the people who wreaked the havoc. Obama was just as mad, but a good portion of his anger was targeted on the members of his own intelligence bureaucracy he said had missed the abundant clues and failed to forestall the attack. Like Bush, he vowed to see that the consequences also fell on the foreign country that gave birth to the plot — Afghanistan eight years ago, Yemen today.

For now, we are conducting a proxy war in Yemen, but that might change. Al-Qaida's local enablers must learn that there is a price to be paid when Uncle Sam is attacked from their bases.

The larger question is how this affects the long-term mind-set and priorities of the new president. Before 9/11, Bush's agenda consisted largely of a set of tax cuts and an ambitious education program (No Child Left Behind), both of which were on their way to easy accomplishment in a compliant Congress.

Obama, on the other hand, came into Christmas Day with an overloaded set of self-imposed tasks. He was winding down one inherited war in Iraq, and expanding another one in Afghanistan. He was renegotiating our relations with other powers in the world and attempting to enlist their help in confronting outlaw regimes in Iran and North Korea. And simultaneously, at home, he was being pressed to rescue a badly wounded economy while lobbying a reluctant but allied Congress to pass controversial, ambitious changes in health care, climate control and financial regulation.

For Obama to establish a new priority would obviously be much more difficult than it appeared to be for Bush. And this new priority would be much less comfortable a fit for Obama than leading a war on terror was for Bush.

Nonetheless, events have their own logic. The Christmas plot appears to have shaken Obama like nothing else that happened in his first year. When he allowed the White House to quote his warning to his Cabinet colleagues that another "screw-up" like that could not be tolerated, he seemed to signal his benign leadership style had reached its limits.

Many have been looking for a similar shift of tone in his dealings with the dictators in Iran and North Korea and in his tolerance for the politics-as-usual maneuverings of many Republicans and some Democrats in Congress.

We do not yet know the fallout of this event for Obama and his government. But it will not surprise me if it is very large.

David Broder is a Washington Post columnist.