Are you better off than you were four years ago?, Ronald Reagan asked his countrymen as presidential candidate in 1980, back in simpler times when our worries extended no further than Communism and inflation. No, America collectively answered, and Jimmy Carter was swept from the White House. But in this age of terrorism, the question relates to physical, not financial, security. Are Americans, and the rest of us for that matter, safer than two years ago?
In a sense, of course they are. Much has been done since that beautiful, cataclysmic autumn morning of 11 September 2001. Even if terrorists were able to infiltrate themselves and their weapons through today's airport security, and into the locked cockpits of armed pilots, never again would passengers allow them to turn commercial jets into missiles.
Probably too, the hundreds of people thrown into custody, and the thousands deported, have indeed removed some terrorists or potential terrorists from America's streets, whatever the price paid in trampled civil rights and innocent lives turned upside down. The new Department of Homeland Security, the new urgency in the work of the FBI and the CIA, the fancy colour-coded terrorist threat alerts - all have increased the sense that something has been done.
And who can argue that two years of the military "war on terror" have not delivered results? The Taliban has been driven from power in Afghanistan, many of al-Qa'ida's most senior commanders are either dead or being milked of their secrets, like snakes of their venom, by skilled and relentless interrogators. The same goes for Iraq, or rather the "Battle of Iraq" as the Bush administration would have it, Act II in the war on terror. Saddam Hussein may be at large, but the majority of his top henchmen have been killed or captured.
The results of this week's ABC News poll come as no surprise: 71 per cent of Americans "are confident" the US is handling terrorism, while only 34 per cent believe it is the biggest problem facing the country (compared with 63 per cent who say it is the economy). But how easily this relative insouciance could vanish. The airliner option is now largely closed to terrorists but a host of others are available.
These days in the US, concern about terrorism is largely limited to the east coast. Live in Washington and you worry about dirty bombs and a biological or chemical weapon attack. But such fears do not impinge on the great American heartland. How quickly we have forgotten Oklahoma City and the 168 people killed by a crude car bomb. How long will it be before the suicide bombers strike - with or without cars? Nothing would create such national panic as an attack on a shopping mall or sports arena in St Louis, say. If you are not safe there, where are you safe? And has the foreign war on terrorism really made America and the world more secure? Despite overwhelming initial successes in Afghanistan and Iraq, the US is fighting guerrilla wars, of unknowable duration, in both places. The invasion of Iraq in particular estranged it from many friends and allies, whose co-operation is vital if terrorism is ever to be eradicated. Iraq has also distracted America's attention from Afghanistan, where Taliban and al-Qa'ida elements appear to be regrouping.
If America faces a greater risk from "retail" terrorism - suicide bombings and the like - the danger of "wholesale" terrorism involving nuclear or other unconventional weapons has also grown. Preventing the proliferation of these weapons has long been a top foreign policy goal of US presidents, and was the mendacious public justification for the attack on Iraq. Yet the fate of Saddam will surely have the perverse effect of making aspiring WMD owners more determined to acquire them.
Iran will certainly have noted that the main reason that the US has not attacked North Korea, its fellow member of the "axis of evil", is because Washington suspects Kim Jong Il may have such weapons already. And if North Korea has them, it will surely sell them, or the means of delivering them.
Every day, the folly of the straitjacket which the "war on terror" imposes on American foreign policy becomes more apparent. You are either with us or against us, Mr Bush told the world, 10 days after the twin towers fell. Yet the equating of all types of terrorism, of the al-Qa'ida variety with the Palestinian variety in particular, has locked America still more tightly into the Israeli camp.
This has made a resolution of the Middle East crisis even more remote. Instead, violence has increased, helping recruit a new generation of the terrorists. Iraq too was forced into this rigid mould, as the President and his men implied, month after month, that Saddam had a hand in the attacks.
Not surprisingly, two-thirds of Americans believe that the road to 9/11 passed through Baghdad. But it is unlikely that Saddam's overthrow makes them sleep much easier at night. Are they safer than two years ago? In a narrow administrative sense, perhaps yes. But the broader answer is no. Not only because that terrible September day destroyed for ever an American innocence and sense of invulnerability, but because Mr Bush is sowing a new whirlwind of his own. And the answer to the question may yet bring down this presidency, as Reagan's destroyed that of Jimmy Carter.