The enemy within

The worst peacetime attack on US soil killed 168 people

By BBC News Online's Kevin Anderson in Washington

The Oklahoma City bombing was a pivotal event in American history. It was a loss of innocence, of naivety. And it changed the way Americans looked at terrorism.

In the end, the deadliest terrorist of all was a clean-cut boy from Buffalo

Analyst Mark Potok

For decades, the debate amongst terrorism analysts was when there would be a major attack on US soil, said Frank Cilluffo, an expert on terrorism at the Center for Strategic and International Studies.

That debate ended abruptly with the bombing of the World Trade Center in 1993 and the bombing of the Murrah federal building in Oklahoma City in 1995, he added.

And instead of looking for threats abroad, Americans suddenly became aware of the enemy within.

Changing face of terrorism

"For many, many years, Americans thought of terrorists as Arabs, period," said Mark Potok, editor of the Southern Poverty Legal Center's Intelligence Report. The report tracks hate groups and extremist activity in the US.

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In the hours after the Oklahoma City bombing, fingers pointed to a Middle Eastern organisation, Mr Cilluffo said.

"But in the end, the deadliest terrorist of all was a clean-cut boy from Buffalo," Mr Potok said.

It had a profound effect on Americans.

"It woke the country up from its naivety that everyone loves America. It is not the case. It is not just threats from abroad," Mr Cilluffo said.

Lone wolf

To meet this new threat, the country dramatically stepped up its counter-terrorism efforts.

"Oklahoma City changed the landscape in American law enforcement, no doubt about it," said Mr Potok.

The FBI hired 500 new agents to investigate domestic terrorism, he said. Virtually every state and federal law enforcement agency formed a domestic terrorism unit, he added.

And in the wake of the bombing, the focus turned from groups abroad to anti-government militias.

What can you do to stop a lone wolf in an open society? It is a fundamental question. You do not want to build too many walls

Terrorism expert Frank Cilluffo

"Law enforcement, like many other groups, tended to view these groups as a joke" before the bombing, Mr Potok said.

"It was hard to take them seriously. They said that stickers on the back of signs gave secret directions to invading UN troops. They said that a secret weather machine in Brussels was destroying American agriculture," he added.

But the bombing in Oklahoma City changed that forever, Mr Potok says.

However, the initial backlash against the militias was heavy handed and perhaps unwarranted, according to Mr Cilluffo.

McVeigh was a lone wolf, not a part of a larger movement. "He went to the fringes of American society and found they did not reaffirm his beliefs. He thought they did not go far enough," Mr Cilluffo said.

And it forced the country to ask questions about its response to this new threat.

"What can you do to stop a lone wolf in an open society? It is a fundamental question. You do not want to build too many walls," he said.

That would threaten the American way of life, and the battle would already be lost, he added.

Psychological impact

But Mr Cilluffo has come away with a sense of hope in the wake of the Oklahoma City bombing.

The impact of terrorism is more than the sheer physical devastation of a bombed out building and the loss of 168 lives. Terrorism is just as important a psychological weapon.

The bombing changed the way America looked at terrorism

Groups do not claim responsibility for terrorism because "it keeps people on edge," he says. It is the fear of not knowing who carried out the attack and where and when they might strike next.

Other countries have learnt to deal with the psychological uncertainty, but this was new for the United States.

Mr Cilluffo recently went to the observance of the anniversary of the Oklahoma City bombing.

At the museum, there is a section with personal effects from those who died in the bombing. "There was a sneaker there my daughter has. It touched a raw nerve," he said.

But he left with a sense of pride. The community had demonstrated strength and resilience, he said.

He said that it highlights what could be the American response to terrorism. "We will prevail. You will fail," he said.