Hubris

From Fortune:

For the first time, technology permitted drilling below more than a mile of water, a hostile environment of total darkness, crushing pressures, and brutal temperatures. Sea-floor operations were carried out with remotely operated vehicles, known as ROVs -- unmanned subs with stubby arms that could connect sections of drill pipe or wield tools to cut through steel. Advances in seismic imaging made it possible to locate hidden oil deposits. Drilling in deepwater was risky and expensive; a single well could cost more than $100 million. But the payoffs were huge. The gulf had particular appeal: The U.S. offered a stable democracy, low taxes, and minimal regulation, as well as nearby refineries and an insatiable market.
BP rushed in, acquiring offshore leases, becoming the biggest player there. Over time, the deepwater gulf emerged as the engine of new U.S. oil production. All this was encouraged by American politicians, who cut taxes for offshore drilling and opened up new swaths of ocean for exploration. Meanwhile the government's Minerals Management Service -- the drillers' chief regulator -- operated like a promotional arm of the industry. Just about everybody, it seemed, liked offshore drilling.

Bold mine.  The article is well worth the read.