One lesson to be learned from the oil spill in the Gulf of Mexico, the largest environmental disaster in U. S. history, is that governments must lead in responding to large-scale catastrophes.

BP's latest attempt to plug the gushing well with the so-called "top kill" method failed again on May 29. The gushing well has so far spewed about 18 million to 40 million barrels of oil into the Gulf of Mexico.

The credibility of the U.S. government' s leadership in dealing with this disaster has been widely questioned and criticized by domestic politicians.

"The American people deserve to know why the administration was slow to respond, why necessary equipment was not immediately on hand in the area and why the president did not fully deploy Cabinet-level federal officials" to the Gulf Coast until April 30, said U.S. Representative Mike Pence said.

While President Barack Obama has defended himself from the scathing criticism, he also admitted the federal government did mess up by overestimating the oil industry' s abilities and thus relying on them too much in tackling the disaster.

As a result, in the first four weeks, BP was the only player to estimate the amount of leaking oil and take whatever actions to prevent the oil spill from spreading, which all failed. Official supervision or regulation was missing.

U.S. conservation groups have strongly denounced this absence of leadership by their federal government.

"BP has every financial incentive to downplay the scale of the spill and the damages," says Jeremy Symons, senior vice president for conservation and education at the National Wildlife Federation.

The Obama administration has tried to defend itself on two points:

First, the U.S. Oil Pollution Act of 1990 gave oil companies, and not the government, primary responsibility to prepare for a well spill, including providing boom and skimmers and deploying them when needed, then controlling any accident and cleaning it up.

Second, the government did not have better technology than BP' s to fix the problem effectively.

"What is true is that, when it comes to stopping the leak down below, the federal government does not possess superior technology to BP," Obama said.

A U.S report, however, disclosed two more untold incentives of the government.

"Mother Jones", a U.S. journal, recently published an article entitled "Obama' s Sluggish Oil Spill Response," which analyzed two possible reasons for the administration's reluctance to take charge of the recovery effort.

One was that "no one -- not BP, not the administration -- seems to know how to stop the gushing well. Nor do they know just how bad this mess could get. The administration would prefer that the blood stay on BP's hands."

The other was that, just 18 days before the BP-operated Deepwater Horizon well blew out, the White House announced a vast expansion of offshore drilling. Hence the federal government wanted to keep a low profile to avoid questioning of its judgement on the drilling expansion.

Obama argued the federal government had been in charge since the moment the disaster began. But that does not give the American people what they want: stop the oil spill.

Oil had hit more than 160 km of the shoreline of the U.S. state of Louisiana, state governor Bobby Jindal said last Wednesday. The Commerce Department declared a "fishing disaster" recently in the seafood-producing states of Louisiana, Mississippi and Alabama due to the spill, which has also led to huge losses to Florida's tourism industry.

After Hurricane Katrina, American academics reached a conclusion on the role of the government in dealing with catastrophic disasters.

"The federal government does have a unique and important role to play," James Carafano, Senior Research Fellow of the Heritage Foundation, wrote in his essay "Improving the National Response to Catastrophic Disaster."

Facing catastrophic disaster, governments cannot escape from playing their irreplaceable role and should take immediate actions. Governments across the world should always bear this lesson in mind.