During a stroll outside the gates of the White House grounds the other night, I thought about the controversy surrounding Tareq and Michaele Salahi and started wondering about ways to sneak into a state dinner. So I took out my notebook and began jotting down the most visible obstacles to overcome. Streets around the White House are blocked with concrete pillars and steel shields; that meant I couldn't show up at the front door in a limo pretending to be President Obama's lost cousin from Kenya. Guards dressed in SWAT-like outfits were stationed at gatehouses around the White House grounds. Leaping over the spear-tipped wrought iron fence and making a mad dash for the Rose Garden wouldn't work, either, unless I could outrun a bullet. As I took notes, an unmarked van with tinted windows showed up and parked across the street from me, engine idling. Call it paranoia, but I began to sense the warmth of an infrared facial recognition scanner -- which made me worry that I could be mistaken for Saddam Hussein. Again. It happened back in 2003, when the threat level was raised to 'orange' by the Bush administration. Highway signs urged citizens to be alert for terrorist activities. For a column, I went to the Jefferson Memorial and asked people if they had seen anything suspicious. The next thing I knew, U.S. Park Police had detained me. 'We hear you've been asking curious questions,' an officer said to me at the time. ''Why are you doing that?' I later learned that a tourist had called police to report that a man resembling Saddam was hanging around the cherry blossom trees, acting strangely. This time, though, I was in front of the White House, not the Tidal Basin. Far more dangerous real estate. Earlier this year, the president mentioned the consequences that even he might suffer if caught trying to break into his residence at 1600 Pennsylvania Ave. 'Here, I'd be shot,' Obama said. The remark had been prompted by the arrest of his friend, Harvard professor Henry Louis Gates, whom a neighbor mistook for a burglar. Entering the White House using the Gates method was definitely out. But if the president thought that he could get shot for trying to enter his own house, then it was possible that I could be considered fair game just for thinking about it. So much for breaking-and-entering fantasies. It seems the only way to get in to a state dinner uninvited is to sashay on in right past the Secret Service. After carefully approaching two police officers who were standing outside their patrol cars, not far from the idling van, I said in my friendliest tone, 'You guys catching any heat over the party crashers?' The officers smiled, as congenial as tour guides -- albeit with guns. 'We're just waiting on the results of the investigation,' one replied. The two had deftly positioned themselves slightly on each side of me. Courteous, but cautious. We ended up talking about street closings. There was a time, for instance, when you could take your grandparents on a drive past the White House, showing them where the president lives without putting them through the agony of a long walk from some overpriced downtown parking garage. No more. 'We closed this block of Pennsylvania Avenue after Oklahoma City,' one of the officers said. Even in death, Timothy McVeigh was still dictating the terms of our freedom. To the east was a closed-off stretch of Madison Street that used to run between the Treasury Department and the White House. You could walk through -- drive through, too, but only old folk seem to remember those days -- with the children waving to the president they imagined was standing in an East Wing window waving back at them. No more. Al-Qaida took that street away. In winter, children used to slide down the snowy steps of the U.S. Supreme Court; in spring, you could picnic on the grounds of the U.S. Capitol. No more. And now come the Salahis, reminding us -- if that investigation proves they sneaked into the White House -- how easy it is to breach it all and that safety measures for which we traded so much liberty amount to little more than an illusion. Milloy is a columnist for The Washington Post. 