Barack Obama’s tone of mild exasperation when tutoring the public often makes his pronouncements grating even when they are sensible. As was his recent suggestion that Americans, misled by media, are exaggerating the threat of terrorism.

The world might currently seem unusually disorderly, but it can be so without being unusually dangerous. If we measure danger by the risk of violence, the world is unusually safe. For this and other reasons, Americans should curb their pessimism.

The Washington Post’s Anne Applebaum recently reminded readers that in three decades of terror the Irish Republican Army murdered more than 2,000. And Italy’s Red Brigades committed many attacks, killings and kidnappings. Both groups had foreign support. The Islamic State is dangerous, but the West has faced, and surmounted, worse. The Islamic State poses neither an existential threat nor even a serious threat to the social cohesion or functioning of any developed nation.

The Obama administration has not recently repeated its suggestion that Vladimir Putin should find an “offramp,” its evident assumption being that Putin inadvertently took a wrong turn, with tanks, into Ukraine. But with Russia, nuclear-armed and governed by an angry man, dismembering a European nation, surely the Islamic State ranks as a second-tier problem.

And a solvable one. An Egyptian diplomat, expressing his nation’s disdain for other Arab nations, once dismissed them as “tribes with flags.” Some of them, including Jordan and Saudi Arabia, could go some way toward proving him wrong, by using their ample ground forces to sweep the Islamic State off the map of the Middle East.

Some Islamic State atrocities are comparable to the elaborately gruesome and protracted public executions (drawing and quartering, disembowelment, burning, beheadings, etc.) that were popular entertainments in the London of Shakespeare’s time. It is not delusional to anticipate a day when barbarism in the Middle East also will recede.

Worldwide, violence has been receding, unevenly but strikingly, for centuries. Steven Pinker, a Harvard psychologist, ascribes the steep decline in violence to numerous factors – governments supplanting anarchy; trade supplanting plunder; rejection of “cruel and unusual” punishments; the decline of interstate war since 1945; the collapse of communism; the pacifying effect of prosperity and its pursuit; cosmopolitanism, meaning the decline of hostile parochialisms due to literacy, travel, education, popular culture and mass media.

As interstate wars declined, Pinker says, civil wars ravaged many newly independent countries. But “civil wars tend to kill far fewer people than wars between states” and “since the peak of the Cold War in the 1970s and ‘80s, organized conflicts of all kinds … have declined throughout the world, and their death tolls have declined even more precipitously.”

Furthermore, there are reasons to reconsider the conventional, and generally correct, skepticism about the efficacy of economic and other sanctions as a response to state violence. They can be protracted futilities, as they have been against Cuba. But the combination of Russia’s vaulting ambitions, its ramshackle economy and its dependence on external financial institutions makes sanctions a plausible tactic against the “ongoing Russian incursion” (Obama’s dainty description) in Ukraine by Putin’s kleptocracy. What is the alternative?

Another antidote to pessimism is recognition that some current disorders are nonviolent and, on balance, desirable. With the Greek crisis, the euro, a foolish financial experiment, might be unraveling, and with it the European Union, an institutional architecture constructed with disregard for its social prerequisites, including a shared political culture and manageable economic disparities.

The 2016 presidential election might resemble the 1980 and 2004 elections in which foreign policy played a prominent role. If so, attention will be paid to Hillary Clinton’s role as secretary of state in the “humanitarian intervention” that reduced Libya to a failed state and an incubator of Islamic extremist groups. In the annals of American blunders, the Bay of Pigs may have been even more feckless, and the invasion of Iraq more costly, but we cannot yet calculate the cost of teaching Iran and others, by our role in the casual overthrow of Moammar Gaddafi, the peril of not having nuclear weapons.

Even so, a sense of proportion, which pessimism impedes, should prevent 2016 from being a competition in alarmism. Pessimism, Pinker says, may be a natural inclination: Imagine the good things that could happen to you today. Now imagine the bad things. Which list is longer? The world is a dangerous place, and can be made more so by America’s unforced errors, as in Libya. Errors can flow from panic bred by unwarranted pessimism.

© 2015, Washington Post Writers Group