Since the Central African Republic descended into crisis a year ago, Chad has been front and centre, described in turn -- and sometimes all at once -- as coup instigator, victim and peacekeeper.
"Ubiquitous but unclear," was how one seasoned observer in Bangui described Chad's presence in the impoverished country where sectarian violence has left 600 dead in a week.
Officially, the troubled country is home to a diaspora of some 15,000 Chadians, but Muslim northerners are often referred to also as Chadians.
The broader "Chadian" community has been the main target of reprisal attacks by majority Christians.
Many Central Africans accuse Chad of masterminding the Seleka rebellion, which disintegrated after its coup in March, releasing rogue fighters who have carried out killings, rapes and looting ever since.
Former colonial power France is leading the ongoing military effort to restore order but Chad's influence over its southern neighbour has been unchallenged for years.
A Western diplomat described Chadian President Idriss Deby Itno as the perennial kingmaker of Central African politics.
The presidency has numerous Chadian advisers, leading to a common perception that the Central African Republic is a Chadian province and its president little more than "Deby's administrator".
Francois Bozize seized power with Deby's support in 2003, but a decade later Chad backed the Seleka rebel coalition that toppled him.
Deby has ruled Chad, now an oil-exporting nation, since 1990.
The demise of Libya's Moamer Kadhafi has stripped Deby of a key ally but also left a regional power vacuum that he appears keen to fill.
Deby this year attempted to revive the moribund Community of Sahel-Saharan States that Kadhafi founded.
The Chadian leader also hosted a regional summit on sustainable development.
Chad currently holds the rotating chair of the Economic Community of Central African States (ECCAS), whose mission in the Central African Republic was blended into the broader 3,000-strong MISCA force.
Chad is one of the force's largest contributors with 650 men, and its most active, but the contingent, operating under the FOMAC (Multinational Force of Central Africa) banner, has largely pursued its own agenda.
"We all act as if the Chadians actually take their orders from the Gabonese command, but we all know that the Chadian soldiers answer first and foremost to Chad," a MISCA officer said on condition of anonymity.
"We all pretend because otherwise it's too much of a headache."
Deby's battle-hardened desert fighters suffered the most casualties in operations to root out Al-Qaeda-linked groups in northern Mali.
That contribution in blood has left France unwilling to raise issues over Deby's dubious human rights record and democratic credentials.
Chad is also home to 950 French troops -- Paris's largest concentration of soldiers abroad after Djibouti -- first deployed in 1986.
During the plundering of "Chadian" and other shops in Bangui last week, the Chadians were the only MISCA troops to dare open fire on the looters.
'Dogs' and 'traitors'
Their patrols ply the war-scarred city leaving a trail of insults in their wake, with Christian residents calling them "dogs" and "traitors".
Members of the 1,600-strong French force have told AFP in Bangui that Chadian peacekeepers had given their FOMAC armbands to Seleka gunmen to help them evade disarmament efforts.
Chadian troops' ambiguous allegiances have added to the confusion on the streets of Bangui.
"The Chadian FOMAC forces are killing us. They're with Seleka, not FOMAC," said one resident, echoing the views of many.
The capital is rife with rumours on the Chadians circulating by SMS.
"There are hundreds of thousands of Muslims in Central Africa. Deby has warned he would not stand idly by if they came under attack," said an official with close ties to N'Djamena.
One Central African politician summed it up: "Nothing will happen without Deby's approval."