If a visitor from a far away galaxy were to land at an American or Canadian university and peruse some of the petitions that were circulating around the campus, he would probably come away with the conclusion that the Earth is a peaceful and fair planet with only one villainous nation determined to destroy the peace and to violate human rights. That nation would not be Iraq, Libya, Serbia, Russia or Iran. It would be Israel.

There are currently petitions circulating on most North American university campuses that would seek to have universities terminate all investments in companies that do business in or with Israel. There are also petitions asking individual faculty members to boycott scientists and scholars who happen to be Israeli Jews, regardless of their personal views on the Arab-Israeli conflict. There have been efforts, some successful, to prevent Israeli speakers from appearing on college campuses, as recently occurred at Concordia University. There are no comparable petitions seeking any action against other countries that enslave minorities, imprison dissidents, murder political opponents and torture suspected terrorists. Nor are there any comparable efforts to silence speakers from other countries.

The intergalactic visitor would wonder what this pariah nation, Israel, must have done to deserve this unique form of economic capital punishment. If he then went to the library and began to read books and articles about this planet, he would discover that Israel was a vibrant democracy, with freedom of speech, press and religion, that was surrounded by a group of tyrannical and undemocratic regimes, many of which are actively seeking its destruction. He would learn that in Egypt, homosexuals are routinely imprisoned and threatened with execution; that in Jordan suspected terrorists and other opponents of the government are tortured, and that if individualized torture does not work, their relatives are called in and threatened with torture as well; that in Saudi Arabia, women who engage in sex outside of marriage are beheaded; that in Iraq, political opponents are routinely murdered en masse and no dissent is permitted; that in Iran members of religious minorities, such as Baha'is and Jews, are imprisoned and sometimes executed; that in all of these surrounding nations, anti-Semitic material is frequently broadcast on state-sponsored television and radio programs; in Saudi Arabia apartheid is practised against non-Muslims, with signs indicating that Muslims must go to certain areas and non-Muslims to others; that China has occupied Tibet for half a century; that in several African countries women are stoned to death for violating sexual mores; that slavery still exists in some parts of the world; and that genocide has been committed by a number of countries in recent memory.

Our curious visitor would wonder why there are no petitions circulating with regard to these human rights violators. Is Israel's occupation of the West Bank and Gaza -- an occupation it has offered to end in exchange for peace -- worse than the Chinese occupation of Tibet? Are the tactics used to combat terrorism by Israel worse than those used by the Russians against Chechen terrorists? Are Arab and Muslim states more democratic than Israel? Is there any comparable institution in any Arab or Muslim state to the Israeli Supreme Court, which frequently rules in favour of Palestinian claims against the Israeli government and military? Does the absence of the death penalty in Israel alone, among Middle East nations, make it more barbaric than the countries which behead, hang and shoot political dissidents? Is Israel's settlement policy, which 78% of Israelis want to end in exchange for peace, worse than the Chinese attempt at cultural genocide in Tibet? Is Israel's policy of full equality for openly gay soldiers and members of the Knesset somehow worse than the policy of Muslim states to persecute those who have a different sexual orientation than the majority? Is Israel's commitment to equality for women worse than the gender apartheid practised in Saudi Arabia?

Our visitor would be perplexed to hear the excuses made by university professors and students for why they are prepared to delegitimate Israel while remaining silent about the far worse abuses committed by other countries. If he were to ask a student about the abuses committed by other countries, he would be told (as I have been): "You're changing the subject. We're talking about Israel now." This reminds me of an incident from the 1920s involving then-Harvard president A. Lawrence Lowell. Lowell decided that the number of Jews admitted to Harvard should be reduced because "Jews cheat." When a distinguished alumnus, Judge Learned Hand, pointed out that Protestants also cheat, Lowell responded, "You're changing the subject; we're talking about Jews."

It is not surprising, therefore, that as responsible and cautious a writer as Andrew Sullivan, formerly editor of The New Republic and now a writer for The New York Times Magazine, has concluded that "fanatical anti-Semitism, as bad or even worse than Hitler's, is now a cultural norm across much of the Middle East and beyond. It's the acrid glue that unites Saddam, Arafat, al-Qaeda, Hezbollah, Iran and the Saudis. They all hate the Jews and want to see them destroyed."

Our intergalactic traveler, after learning all of these facts, would wonder what kind of a planet he had landed on. Do we have everything backwards? Do we know the difference between right and wrong? Do our universities teach the truth? These are questions that need asking, lest we become the kind of world the visitor would have experienced had he arrived in Europe during the late 1930s and early 1940s.

Alan M. Dershowitz is a professor of law at Harvard and author of Why Terrorism Works. This essay is based on a speech he is making at a United Jewish Appeal forum tonight in Toronto.