Warring between nations in the Middle East has been going on for decades.
Currently, trouble is brewing between two more countries in the Eastern hemisphere -- India and Pakistan. Why do they dislike each other?
"They hate each other because they've hated each other from the beginning," said Dr. Kenneth Grieb of the International Studies program at University of Wisconsin-Oshkosh.
Not surprisingly, religion plays a major role in the age-old friction between the two countries, say area experts.
Dr. Clarence Davis, a history professor at Marian College, said he thinks recent events - perhaps even U.S. involvement - may have heated up latent tensions.
Davis said he believes the burner may have been turned up a few degrees when the United States loosened sanctions on Pakistan in exchange for help in the war on terrorism.
Seeking airspace and an ally after declaring war on the Taliban in Afghanistan in October, the U.S. government eased sanctions against Pakistan. That may have given India the impression that the U.S. is siding with Pakistan, he said.
"Pakistan initially was feeling emboldened because the sanctions imposed on it were swept away," Davis noted. The sanctions dealt with trade and international loans.
"The United States had been out to prevent the spread of nuclear weapons, and when both Pakistan and India successfully tested nuclear weapons, the United States pressured them not to develop their nuclear arsenals," he explained.
"We said: 'If you do become a nuclear power, we are going to (impose sanctions).' Both Pakistan and India decided it was in their interest (because of the tension between them) to attain nuclear status and went ahead and took the economic consequences," Davis said. "The consequences damaged Pakistan's economy."
He said American actions also heated up domestic politics within Pakistan and may have led those who oppose the current military regime to step up what Indian is calling "cross-border terrorism," partly to embarrass the Pakistani government and to make improved relations with the United States more difficult."
The geographical closeness of the two nuclear powers adds fuel to the flames, according to Grieb.
"I ask my students: 'How would you feel if the enemy's army was in Chicago< or Detroit?' The capital of Pakistan is about that distance from India's capital.
Davis predicts the U.S. will try to prevent such a war, which he said "would interfere with U.S. efforts to deal with terrorism. But both parties have shown they're willing to go to war."
Grieb said he doesn't believe that loosening sanctions had anything to do with recent tensions, and described the Middle East as an area "of diverse ethnic groups and religions which are mutually suspicious."
Pakistan and India were once the same country -- India under British rule. The dominant religious groups were Hindu and Islam (known as Muslim).
India gained independence in 1947. Pakistan was created to give Muslims living in India their own space. Bangladesh was East Pakistan. India and Pakistan disagreed on who owned Kashmir.
"This area remains in dispute," Grieb pointed out.
"After a war, it was temporarily divided between the two countries," he said. "That temporary state has continued, and India and Pakistan have been unable to resolve the issue of who should control Kashmir.
"The result has been constant tension and occasional wars between the two countries."
Davis said differences between Hindu, the primary religion of India, and< Muslim, the primary religion in Pakistan, lie in the form of the deity worshipped. Muslims worship Allah, or God. Unlike Christians, they don't believe Jesus was the son of God.
The Hindu god takes many forms, often in the shape of an animal, Davis explained. While India has the third largest number of Muslims in the world, its predominant religion is Hindu.
"A devout Muslim looking at the Hindu religion is not going to come back with a positive feeling," Davis said. "Muslims believe there is no god but God, and Mohammed is the prophet of God.
"On the other hand, a person who is Hindu is likely to say, 'Tell us about your beliefs.' They are flexible, and God takes on an infinity of shapes, numbers and images, with a profusion of human and animal conceptualizations of divinity doing all sorts of things we don't associate with religion, including sexuality," Davis said.
"For a devout Muslim, it is offensive to create images of people. Statues are considered a sin, which is why the Taliban blew up the Buddha statues because they believe creating human representations is against God or Allah."
Grieb said he fears use of the term "anti-terrorism" will inadvertently cause more violence in the name of fighting to end terrorism. The term "terrorist" is a subjective term, he says. "It's all in the eye of the beholder."
Those who commit terrorist acts often believe they are trying to liberate their country, Grieb said.
"When Americans think terrorist, they think of bin Laden; when Israelis think terrorists, they think of Palestinians; when Indians think of terrorists, they think of Pakistanis," Grieb said.
"We think we are dealing with something different, and what happened at the World Trade Center is different, but in India's view, how is it different from the attack on their Parliament building in New Delhi in fall of 2001?"