Some pundits are referring to events this week in Iraq as John McCain’s “Waterloo.” That may or may not be true, but it misses a larger point: While the Bush administration has done plenty of end runs around the Constitution, it was unable to repeal the law of gravity and the consequences of its excesses were bound to come crashing down sooner or later. As the president’s handmaiden, McCain was going to get bonked.

Mind you, Barack Obama was nothing if not clever in looking ahead and toward McCain even while he was still battling it out with Whatshername. The agility of he and his staff has enabled him to run circles around a septuagenarian who is stumbling from crisis to crisis and still can’t get his own house in order nearly five months after he secured the Republican nomination.

Among all of the lousy decisions that McCain’s campaign has made, challenging Obama to a game of mano-a-mano by visiting Afghanistan and Iraq surely is the worst.

It is obvious that no one in the McCain camp considered what might happen if Obama accepted his challenge, let alone that the situation on the ground in both hot spots was trending toward validating the Democrat’s policy positions and away from the artifice of the Bush administration and by extension McCain himself.

That situation is made worse by the very whining, much of it directed at the media, from McCain and his surrogates that Phil Gramm decried before he was cashiered. But when he does get coverage — most recently his latest vacillations on Iraq and over-the-top claim that Obama would rather win the election than the war — he suddenly cancels his press availability.

As it is, McCain caught an enormous break from that selfsame media while Obama and Hillary Clinton were slugging it out, but squandered that opportunity to grow his campaign organization and fine tune his policy positions. Judging from McCain’s campaign schedule, he still seems more focused on getting money than votes.

The scene in the photograph above did not happen by accident and is a huge gift for Obama. It is sure to be a part of every post-Election Day media slideshow chronicling how a black junior senator from Illinois came out of nowhere, vanquished a war-hero challenger and ended the Republican hegemony in Washington.

Obama was part of an official Senate delegation for the first two stops of his overseas trip, and General Petraeus was obligated to take him for flyover of the war zone. But the photo has become an overnight classic — the handsome president in waiting and his rugged Centcom commander in waiting captured in profile. You can almost hear them conversing about the rough road ahead over the thump-thump-thump of the chopper blades.

As it is, Obama is unproven on foreign policy and national security, but Prime Minister Nouri Al-Maliki administered the coup d’grace to McCain in endorsing Obama’s withdrawal plan as substantially similar to his own in a major magazine interview only hours before Obama set down in the Green Zone where he was accorded a red-carpet reception.

From there it was on to Jordan, Israel and the Palestinian territories and then what from all accounts will be a tumultuous welcome in Germany, a big wet kiss from Nicholas Sarkozy, the French president and Obama’s equal as an orator, and a London flyby, where the Tories owe their ascendancy to the failings of Tony Blair, who was accurately ridiculed in the U.K. as George Bush’s poodle.

Obama is sure to get a modest bump from his most excellent overseas adventure. But it is sure to be a summer of discontent for McCain supporters if the best he can do in the interim is a lame new TV commercial blaming his opponent for record-high gas prices because he supports a congressional off-shore drilling ban while everyone with a ExxonMobil credit card knows that prices have been trending upward for a decade.

Picking a running mate should give McCain some attention, but before you can say “gas tax holiday” the Democrats will convene in Denver for Obama’s coronation in a packed football stadium and then the Republicans in Minneapolis where the big story will be how much face time that Bush the Party Pariah will be given.

So it may be after Labor Day before McCain can get a significant word in edgewise. Then come the presidential debates, a showdown that will give him chest pains since Obama on his worst day can eat the addled McCain’s rhetorical lunch on his best day. (Memo to McCain: Somalia is not Sudan, Iraq and Afghanistan do not share a border, Czechoslovakia went out of business 15 years ago and the Packers play in Green Bay, not the Steelers.)

And all the while Afghanistan will be hemorrhaging, the economy will continue to tank and the trickle of revelations about torture and other administration excesses will become a torrent as the countdown to the end of Bush’s reign of error begins in earnest.

Is it possible that Obama will coast to victory through a combination of luck and spunk and without really having to prove that he is up to the job? Yes, especially if McCain keeps stabbing himself in the back and getting bonked on the head with the rotten apples falling from Bush’s tree.