Voters are sick and tired of this presidential campaign. In a poll by the Pew Research Center, 6 in 10 Americans said they were exhausted by the campaign — and that was four months ago. Another survey, sponsored by the American Psychological Association, said the campaign had become a source of significant stress in many people’s lives. Among the most stressed-out, not surprisingly, are people who spend time on social media.

The dispiriting ordeal has spurred pop singer Sheryl Crow to launch an online petition asking the two major parties to make the next campaign shorter.

“We cannot sustain another lengthy slugfest like what we have witnessed for the past two years,” Crow wrote, summarizing the campaign as “ugliness … nonsense and fear-mongering.” More than 58,000 people, including Bette Midler and Courteney Cox, have signed the appeal.

But it’s not going to happen — and it shouldn’t.

Crow and other reformers point enviously at Britain and Canada, where elections are blessedly brief. Canada chose a new prime minister last year; it took less than three months, from August to October, and some Canadians complained that even that was too long. Our campaign will have lasted roughly 23 months by election day, if you count the first “exploratory committee” announcement as the starting gun.

But the comparison with parliamentary systems is unfair. In Britain and Canada, there are no primaries; parties have elected leaders who become ready-made candidates for prime minister whenever an election is called.

Here at home, there’s no national authority in charge of our campaign calendar; individual states set the timing of primaries and caucuses. They jostle for dates at the front end of the calendar to maximize their influence (and, in Iowa and New Hampshire, their midwinter hotel bookings).

“The (U.S.) election process is the longest in the world because no one is in charge of it,” noted Steven Schier of Carleton College.

Structural issues aside, shorter campaigns are a bad idea on the merits — because we need time to figure out who our presidential nominees really are, warts and all.

One good thing about our process is that it allows relatively unknown candidates to rise to the top of the heap.

Bill Clinton was so small-time before the 1992 primary campaign that his name wasn’t included in some early polls. Bernie Sanders was an obscure Senate gadfly before he started running in 2015. Both managed to earn broad support — but they needed months to do it.

This year’s nominees, Donald Trump and Hillary Clinton, have been making national headlines for decades — but there was plenty of new information voters needed to learn about them, too. (They might have preferred not learning some of it — but they’re surely better off knowing before election day than after.)

In only the last six weeks, we’ve learned that Trump didn’t pay federal taxes for several years, that he mistreated Miss Universe contestants and wandered through their dressing rooms, and that he bragged (while wearing a microphone) of grabbing women by the, er, crotch.

During the same period, we’ve had an unprecedented look inside the workings of the Clinton campaign through stolen documents published by WikiLeaks, and we’ve learned that the FBI is reviewing newly discovered emails that apparently belong to Clinton aide Huma Abedin.

“Ask yourself, ‘What do I know today about a candidate that I didn’t know three months ago?’” Kathleen Hall Jamieson of the Annenberg Public Policy Center at the University of Pennsylvania, said recently. “If the answer is, ‘I know something that’s important to me,’ then the longer campaign has helped you.”

Some of those discoveries might have come to light in a shorter campaign, but not all.

For one thing, there are fewer investigative reporters and fewer media organizations digging into the candidates’ pasts than in earlier years. A shorter campaign would have given both candidates a better chance to keep their dirty laundry out of sight.

For another, this election features two unusually secretive candidates.

Even after more than 18 months of campaigning, there’s still more that voters deserve to know. They ought to know more about Trump’s business entanglements, including what’s in his tax returns. And they have a right to know whether the FBI’s latest email discovery means that Clinton is in serious trouble.

So here’s a bold proposal: We ought to lengthen this campaign, not shorten it. Let it go into overtime. Keep the polls open and hold off counting votes until all those questions are cleared up.

OK, I’m only kidding. Even I agree that this election has run too long. But be careful what you wish for. A shorter campaign might not be an improvement.

Doyle McManus is a columnist for the Los Angeles Times. Readers may send him email at doyle.mcmanus@latimes.com.

Over the last five years, President Barack Obama has placed a big bet on Moscow and Tehran. He tacked away from the United States’ historic allies in the Middle East — Israel, Saudi Arabia and Turkey — to create space for the Russians and the Iranians in the regional security architecture. Again and again, that wager has come up craps.

The Iranian nuclear deal was supposed to usher in a new era in U.S.-Iranian relations. Instead, it has spawned a Russian-Iranian alliance. The most powerful ground troops working with the Russian air force to save Syrian President Bashar Assad are under the control of the Iranian Revolutionary Guards — who also wield inordinate influence, directly and through proxies, over the forces besieging Mosul, Iraq. In consequence, the Russian-Iranian alliance is well on its way to building a corridor of subservient states stretching from Tehran to Beirut.

Obama has turned a blind eye to the long-term risks of this corridor, because he hopes that Tehran and Moscow will work with him to build a concert system in the Middle East: a club of nations that, united in their enmity to al-Qaida and Islamic State, will cooperate to contain the worst pathologies of the region.

As the president suggested immediately after signing the Iranian nuclear deal, the club was even supposed to help with challenges beyond Islamic State. “(B)uilding on this deal,” he said, “we can continue to have conversations with Iran that incentivize them to behave differently in the region, to be less aggressive, less hostile, more cooperative … in resolving issues like Syria or what’s happening in Iraq, to stop encouraging Houthis in Yemen.”

But Tehran has not moderated — and now the Houthis, with Iranian missiles and no doubt with Iranian encouragement, are launching attacks on U.S. ships in the Red Sea.

Obama is not the first American president to make such a gamble on a long-standing adversary. In 1953, when President Eisenhower assumed office, he too sought to stabilize the Middle East by co-opting the leading anti-Western power of the day — Gamal Abdel Nasser’s Egypt. Eisenhower believed that making Egypt a partner in regional security would soften Nasser’s behavior and entice him to organize the Arabs behind the West in the Cold War.

Believing that the association of the United States with Zionism and British imperialism was poisoning American relations with Middle Eastern Muslims, Eisenhower worked to prove to Nasser that the U.S. would help him achieve his nationalist goals, even if those came at the expense of British and Israeli interests.

Thus, for example, Eisenhower brought enormous pressure on the British to withdraw their troops from Egypt, where they had enjoyed a continuous presence for many decades.

This policy came to its logical conclusion 60 years ago, when, at the climax of the Suez crisis, Britain, France and Israel launched coordinated attacks against Egypt. Eisenhower’s opposition to his allies was extreme. Working in parallel with the Soviet Union, he brought the British economy to the brink of destruction and demanded that the invaders stop in their tracks and evacuate Egypt immediately. The United States’ allies buckled under the pressure.

Eisenhower’s policy handed Nasser the victory of his life, and the Egyptian leader’s reputation in Arab politics skyrocketed to mythic heights. How did he repay the American president for his support? By becoming more radical, more anti-Western and more pro-Soviet.

Nasser’s rise, like that of Russia and Iran today, had a profoundly destabilizing effect on the Middle East, leading, among other results, to regime change in Syria and Iraq, and the deep penetration of the region by Soviet power.

Richard Nixon, Ike’s vice president, recounted in the 1980s that about a year before his death Eisenhower admitted that his support for Egypt was his major foreign policy mistake. “(S)aving Nasser at Suez didn’t help as far as the Middle East was concerned. Nasser became even more anti-West and anti-U.S.,” Eisenhower said. He also affirmed, Nixon wrote, “that the worst fallout from Suez was that it weakened the will of our best allies, Britain and France, to play a major role in the Middle East or in other areas outside Europe.”

Eisenhower came to realize that Israel was the United States’ truest friend in the Middle East and that courting adversaries is a very risky business. It is too late for Obama to learn that lesson, but not for his successor, who will have two examples not to live by.

Michael Doran, a former White House advisor on the Middle East, is a senior fellow at the Hudson Institute and author of “Ike’s Gamble: America’s Rise to Dominance in the Middle East.” He wrote this for the Los Angeles Times.