Terrorist cowardice was in full view last week, as bombs ripped through Istanbul, and in other recent attacks that devastated the Indian cities of Bangalore and Ahmedabad. Those atrocities, which killed or injured hundreds of people, should remind us that the next attack can come at any time or place. Americans who have been watching the global terrorism problem and expressing relief that it has avoided the U.S. homeland since Sept. 11, 2001, ought to pay close attention.

When a U.S. ally — and Turkey and India rank among the staunchest — suffers a terrorist strike, Americans should feel the pain almost as if they had directly sustained it. That is because the miscreants who lashed out in Istanbul, Bangalore and Ahmedabad are fighting against a way of life that ties Americans to Turks and Indians as surely as the air that they collectively breathe.

If the decent residents of the planet appear dazed, disorganized and detached from one another in their reactions, terrorists will gain ground. Thus, Washington, Ankara and New Delhi, along with other allies, have an obligation to respond with all the alertness, creativity and intensity at their disposal — and to do so in the context of a proactive, comprehensive, consistent, long-term strategy that aims to eliminate as many roots of terrorism as possible.

What have we learned from the latest attacks?

One familiar lesson is that terrorists tend to hit the easiest and most vulnerable targets. In Ahmedabad, those were markets and hospitals; in Istanbul, the choice was a pedestrian zone.

Second, terrorists often use a one-two punch that was best exemplified on 9/11, with the first attack on the World Trade Center in New York followed by another. That approach maximizes injuries to initial victims, first-responders and the curious — precisely what happened in Istanbul. In Ahmedabad, the attacks were particularly sinister in that the perpetrators planted bombs at the hospitals where the victims of their earlier carnage had sought medical care.

Such behavior ties in with a third lesson, that terrorists today, to help guarantee widespread coverage, aim for as many casualties and as much horror as possible — a fact that should shock but not surprise onlookers.

Fourth, acts of terror are designed to have an impact well beyond their immediate victims. Terrorists may be trying to intimidate governments, destabilize societies, disrupt economic success — a particular worry for Bangalore, India's information-technology center — force policy changes, ignite international conflicts or stoke communal tensions.

A fifth lesson is that terrorist devices and tactics need not be complicated to deliver terrible results. Simple bombs stashed in trash bins — the approach in the Istanbul attacks — have been in use the longest.

Sixth, the coordination of multiple blasts, specifically in India, suggests growing expertise, which brings up the possibility of ties between local groups and organizations in other countries. Fortunately, there is no single, united, international terrorism movement. Still, global links among like-minded groups are indisputable and expanding, especially through technology.

A seventh lesson is that little- known, wannabe terrorist groups are always showing up, yearning for credentials and recognition. The "Indian Mujahedeen," which took credit for the Ahmedabad attacks, just as it had for blasts in Jaipur a few months ago and others, is merely a recent example. The danger may well be significant, especially if it portends serious home-grown terrorism in India, but one should guard against allowing such groups a psychological advantage that they do not deserve, which points to a seventh lesson:

The troublemakers, despite their viciousness, are hardly omnipresent; in addition, terrorists are commonly less numerous and weaker than they would have people believe.

Finally, though the world has witnessed in Turkey and India more of the death and destruction that usually accompanies terrorism, it should not waver in its resolve. Terrorists are relatively few, with limited options and uncertain longevity, while good people are legion, with infinite possibilities and history on their side — if they stand together.

John C. Bersia, who won a Pulitzer Prize in editorial writing for the Orlando Sentinel in 2000, is the special assistant to the president for global perspectives at the University of Central Florida. He wrote this commentary for McClatchy-Tribune News Service.