Mr. Scaroni, a graduate of Columbia Business School in New York with a master’s degree in business administration, took the top job at Eni in 2005 after spending much of his career outside Italy and the oil business. He has been gradually reshaping the company into more of a machine for finding and producing oil and natural gas and less of the lumbering state conglomerate that had toiled in the second tier of global oil giants.

Mr. Scaroni, 66, also has the crucial task of maintaining Eni’s relationships with a group of fossil-fuel-rich but prickly host countries that include Iraq, Libya, Russia, Venezuela and, elsewhere in Africa, Angola and the Republic of Congo. He regularly turns up in places like Baghdad or Brazzaville that might give other chief executives pause.

During the interview, the Zubair field in Iraq was on his mind. “We have a company with 150 expatriates in Iraq, with a huge effort for security, and the economic result for us is very little, since we are paid $2 per barrel,” he said. “From time to time, we ask ourselves: Is it worth it?”

Eni is the largest foreign producer of oil and gas in both Algeria and Libya. Eni executives say they were surprised and shocked by what happened to BP and Statoil, which are partners in the Algerian plant that was seized, and are tightening up their own security measures. They note that Eni already has large numbers of Algerian troops inside the perimeters of its Algerian sites, while troops apparently were not posted inside the seized complex at In Amenas.

So far, Mr. Scaroni has smoothly sailed Eni through Libya’s chaotic transition from the regime of Col. Muammar el-Qaddafi to a new government that is still trying to find its balance. Unlike most other oil companies, Eni thrived under the Qaddafi regime, developing new fields and building a $9 billion facility at Mellitah, west of Tripoli, to pipe natural gas under the Mediterranean.

Mr. Scaroni was quick to go to Benghazi in April 2011 to meet the rebel leadership, even before Colonel Qaddafi’s fall. Since then, Eni has restored most of its Libyan production, which represents 14 percent of Eni’s oil and natural gas output.

But Mr. Scaroni knows he cannot be complacent. The Wafa field, an important Eni site in Libya, is 35 kilometers, or 22 miles, east of In Amenas. The Libyans do have a special incentive for protecting the field: It keeps the lights on in that country, producing 50 percent of the gas that fuels Libyan power plants.