"A year ago he looked like he was on his last legs but the situation has clearly changed in his favour," said an international diplomat who requested anonymity. "Before April he was Deby Couchant [lying down]; now he has become Deby Rampant [rearing-up]."
But while analysts say that for the moment his government seems more secure, they do not say that he is any closer to finding long-term solutions to the armed conflicts taking place in the country, particular in the east near Sudan's Darfur region where between 120,000 and 170,000 Chadians have been displaced from their homes.
Nor are there signs that quality of life is improving for Chadians anywhere. "Deby is a warrior; he is wholly focused on his own survival," said one senior humanitarian official who did not want to be named. "It is very sad to see how, despite the country's new oil wealthy, basic human services are utterly neglected. Most people have nothing."
In 2005 and 2006 it looked like Deby had overstretched himself. He faced attempted coup d'etats, mass desertions from the army, and defections from his inner circle including senior government officials from amongst his tightly knit Zaghawa ethnic group.
In April 2006, the rebel Front Uni pour le Changement (FUC) rebel group advanced from the east and entered parts of N'djamena. They were eventually repulsed but only after heavy fighting and indirect military support from France, the former colonial power.
That close call seems to have awoken Deby. "From then on he started to take some daring action's that some of us thought he would never pull off, but he did," said an analyst in N'djamena.
One was to still hold - and win - elections in May 2006, less than a month after the attack on N'djamena. Another was to convince Sudanese president, Omar al-Bashir, who Deby accuses of backing the rebels opposed to him, to attend his inauguration less than one month later.
Big oil revenues
Deby quickly took on the big oil companies. In August, he unilaterally changed the terms of agreements he had made with ChevronTexaco and Pretronas, suddenly demanding they pay hundreds of millions of dollars in taxes.
Even more daring, Deby abrogated an agreement with the World Bank which stipulated most of Chad's oil revenue should be invested in social services and saved for future generations.
"He is now swimming in oil money with about US $1.5 billion last year and he can basically do with it what he likes," an analyst said.
The result of the cash windfall is clear at the presidential palace in N'djamena where dozens of troops sport shiny new automatic weapons. The government has also reportedly ordered five new combat helicopters.
Details on how much Chad is spending on arms is hard to come by but the minister of state, Adoum Younousmi, told IRIN on Saturday that the government has no shame in admitting that it is spending a lot.
"Like all states we must buy arms to defend the integrity and sovereignty of its territory," he said
He also admits that military spending comes at the expense of social services. Teachers, health workers and other civil servants have all been on strike since 2 May, demanding pay rises and backdated salaries.
Minister Younousmi argued that oil money should not be used to pay civil servants. "Oil resources are too volatile and cannot serve as a [fixed cost] to increasing salaries," he said.
"If we increase salaries today we will have problems tomorrow."
Deby's revitalisation has come from diplomacy as well as money.
In December, Deby negotiated an agreement with Mahamat Nour, leader of a 13 member coalition of rebel parties and his main rival. Nour became minister of defence and two other FUC commanders were given ministerial posts.
Thousands of FUC combatants are also being integrated into the army. Their intimate knowledge of the caves in the east they were once hiding out is expected to be invaluable in helping the army flush out the other rebel groups that are still there.
Yet Deby's alliance with Nour poses dangers for Deby - indeed some believe it could be his undoing.
Nour gains his support from the Tama Arab ethnic group, which has traditionally been opposed to Deby's ethnic Zaghawa, who dominate Chad politically and militarily. Some Zaghawa fear that Nour, his Tama entourage and FUC body guards have come to N'djemena as a Trojan horse to attack from within.
The alliance between Deby and Nour has also deepened existing division within the Zaghawa. Several cabinet-level government officials and army officers have since defected.
One of the defectors, Mahamat Nouri who was once Deby's minister of defence and then ambassador in Saudi Arabia until defecting following the May elections, formed the Union of Forces for Democracy and Development (UFDD). In October the UFDD attacked and captured for 24 hours Abeche, a regional capital and aid hub in the east.
Another rebel group formed by defectors, the Rally of Democratic Forces (RADF) advanced to Biltine in October, one of the other regional capitals of the east.
Various Arab groups have also aligned themselves with Nouri while still others have created separate rebel coalitions against Deby.
It is unclear whether the rebellions are growing or just becoming more convoluted. Either way, Deby is unlikely to be able to negotiate a comprehensive solution - but he does have militarily muscle to at least contain them.
As the N'djamena-based analyst said: "How all these alliances affect the big picture is anyone's guess, but while Deby is not going to be overthrown in the short term, over the long run stability is eroding."