As the mid-September deadline for a cease-fire in Nigeria's oil war approaches with no sign of a mass surrender by rebels who have shattered the country's oil production, President Umaru Yar'Adua is preparing for an all-out army offensive, according to published reports.

Earlier offensives failed to crush the rebels, but this time Yar'Adua will have Israeli warships and trainers to help his forces operate in the swampy Niger Delta.

That's Nigeria's main oil-producing region and the center of the insurgency headed by the Movement for the Emancipation of the Niger Delta.

Indeed, there are indications that the Israelis, who have long operated in Africa, are looking to establish close military links with Nigeria, one of the continent's main oil producers.

Israel's deputy prime minister, ultra-right hawk Avigdor Lieberman, is currently visiting Nigeria as part of an African tour.

He is accompanied by a posse of businessmen, most of them reported to be arms dealers, security advisers and representatives of Israel's military industries.

Yar'Adua declared an unconditional 60-day amnesty July 15 for all rebels who laid down their arms in their 5-year-old war against Nigeria's oil industry. The amnesty expires Oct. 4.

MEND is a loose alliance of rebel groups who are demanding a greater share of the country's oil revenues from a government that is plagued by corruption and inefficiency.

Government officials said they expected between 8,000 and 10,000 fighters would accept the amnesty. But only a few hundred of the estimated 12,000-15,000 rebels have handed in their weapons.

Several rebel commanders have engaged in talks with the Abuja government, which has been doling out large amounts of money to induce the chieftains to bring in their men. Oil industry sources say the rebels use the money to buy new arms.

The vast majority of the rebels remain at large, claiming the government refuses to address their demands to improve the living conditions of the delta's impoverished tribes.

They have continued sporadic attacks on oil installations despite the amnesty -- including torching an oil depot in Lagos, the country's economic capital far to the northwest -- and warned they will resume major operations once the 60-day cease-fire they declared in July expires Sept. 15.

"Our solemn pledge to the people of the Niger Delta still remains to emancipate the region from the forces that have held it down for more than 50 years with divide-and-rule, monetary inducements and treachery," the MEND leadership declared in an Aug. 22 statement.

Despite its newfound Israeli support, the Nigerian military, one of the most powerful in Africa, faces a major challenge in rooting out the rebels in the vast labyrinth of mangrove swamps, creeks and rivers in the Niger Delta of southern Nigeria.

The rebel operations in the delta against facilities run by oil majors like Anglo-Dutch Shell, Chevron of the United States, ENI of Italy and Total of France have slashed Nigeria's all-important oil production by half over the last two to three years, a 20-year low.

Nigeria is the United States' fifth-largest oil supplier. Overall exports have fallen by 40 percent since 2006, contributing to instability in world energy markets.

The damage to Nigeria's oil industry has allowed Angola, hundreds of miles to the south with only a third of Nigeria's reserves, to take over as Africa's leading oil producer.

Military force is unlikely to resolve Nigeria's crisis or halt what the Financial Times calls the "precipitous decline" of one of the world's largest oil industries.

The FT has warned that only "radical action" by the Abuja government will bring the crisis to an end at a time when oil revenue is tumbling and the country grapples with increasingly violent Muslim extremists in the north.

Yar'Adua, it said, must be more decisive in checking "fast-eroding state authority and the failure of the government to regain control of a resource on which the nation's development depends."