In September 2012, Sudanese President Omar Al Bashir and his South Sudanese counterpart, President Salva Kiir, clasped hands grinningly in the international spotlight at the end of a successful summit in Addis Ababa, Ethiopia. They had just signed a comprehensive peace mapping out the relationship between the new neighbours, a little more than a year after South Sudan became independent in July 2011. It was also a deal that pulled the states back from the brink of war.
In subsequent months, a polite game of diplomatic ping pong between the two Sudans repeatedly state a sincere commitment to peace. But these commitments look increasingly hollow as one deadline after another set by African Union mediators slip by. The promised peace has not left the piece of paper it was written on.
This hiatus in the peace process may be coming to an end, but not in the way the mediators had hoped. In recent weeks, reports have emerged of a build-up of troops along the countries' shared border, including in hotspots like the disputed Abyei area and the oil fields of Heglig. Incidents along the border are already taking place, with reports that 24 people have been killed in recent weeks.
Border dispute chokes South Sudan's oilfields
The white gloves of diplomacy, it seems, are being peeled off for another fight. On February 11 in Khartoum, Bashir accused South Sudan of having become "devoted to creating conflicts", adding: "We are advocates of peace, but peace will not be at any cost. We have given everything and we do not have anything new to offer."
The South Sudanese government went a step further the next day, announcing their forces were ready for a possible attack. "We are concerned again about this hawkish mindset, about the ruling elites in Khartoum who would want to escalate the situation along the border and possibly provoke a war between the two countries," Sudan's deputy defence minister Majak D'Agoot said.
Too weak for peace
South Sudan's independence has left both countries' economies in a perilous state, weakening their governments' ability to implement the peace deal. The secession of South Sudan, home to 75 percent of the country's oil reserves, shocked Sudan's economy by depriving its government of more than half its revenues.
Although many expected Sudan would recoup some of its lost oil income by levying transit fees on South Sudanese crude, the two countries could not agree - until the September deal was signed – on the level these fees should be. The negotiations to resolve this issue broke down a year ago when South Sudan discovered that Sudan had been selling some oil in lieu of payment for transit fees. In a self-destructive fit of anger, the South closed down its entire oil production - causing the government to lose 98 percent of its revenue.
Both countries' governments also face rampant inflation and rising food prices, creating the potential for popular discontentment.
Politically weakened by their failing economies, both presidents returned from the signing in Addis Ababa last September to face criticism over the deal from hardline elements in their own parties.
In Khartoum it came from Islamist hardliners, who objected to the "four freedoms" agreement that would give southerners the right to remain and work in Sudan.
The head of the far-right Justice and Peace Forum, Al Tayeb Mustafa (who is also President Bashir's uncle), declared that his faction would fight the "four freedoms" by "all available political means", adding: "If the government has failed to bear its responsibility, then it should concede power to the people so that they can choose who is capable of defending their rights and holy [lands]."
In Juba, South Sudan's capital, opposition to the Addis agreement came from within the military. Some generals were opposed to making peace with President Bashir's government - a regime they had fought for more than 20 years - particularly when their former comrades in the Sudan People's Liberation Movement North (SPLM-N) across the border had gained nothing from independence.
Faced with these internal threats, maintaining power - not delivering peace - became the priority for both sides.
In November 2012, Sudan's government announced it had locked up alleged Islamist coup plotters. A month earlier in South Sudan, President Salva Kiir warned his military against staging a coup and last month sacked more than 20 senior commanders.
On February 18, Kiir removed 118 more senior military officers from active service. Barnaba Marial Benjamin, South Sudan's minister for information and broadcasting, explained the move as security sector reform, dismissing suggestions this had anything to do with their potential disloyalty. "The president still trusts them [the generals]. He has hope in them and they should show good examples in accepting the changes," Benjamin said.
Back on track?
Despite domestic political pressure, last month the African Union made every effort to get the stalled process back on track, holding two presidential summits within three weeks.
The first meeting on January 5 was a success, seeming to resolve the sticking points preventing implementation of September's deal. President Kiir agreed once more to the complete withdrawal from a border zone known as the "14 mile area", a point of deep contention with the South's military. For its part, Sudan agreed to ease its condition that a demilitarised border zone be established before South Sudanese oil could be exported through Sudan again. Sudan had insisted on prioritising border security because it believes the SPLM North rebels on its side of the border, part of the South's army before independence, continue to be supported by Juba - a charge Juba denies.
Things looked like they were heading in the right direction. On January 17, South Sudan wrote to the UN Security Council that it had "completed the withdrawal of all its troops" from the border area in compliance with the agreement.
But it had not. Instead, Kiir had apparently returned to Juba after the January 5 summit to find some of his generals unhappy at withdrawing from the "14 mile area". "President Kiir's biggest threat is not Sudan but his own army," quipped one diplomat.
With no progress on implementing the January 5 agreement, the two presidents met again in Addis on January 25. Khartoum had reverted to its previous stance of requiring a border zone be set up before oil were to flow again. Far from having withdrawn, South Sudan's army was present in several places over the temporarily agreed-upon border.
The second summit was a failure. Most negotiations are now on hold and meetings at the technical level are no longer taking place. Meanwhile, the one issue holding up the others - the 14 mile area - is being addressed at presidential level.
Abibo Eric Ngandu, the AU's spokesman for the High Level Panel running the mediation, said: "The Panel is facilitating discussions between the presidents on the unresolved matter of the '14-mile area', which can be resolved only by the presidents." He added that the committee dealing with the issue of border security "will not be able to take its work any further" until this issue is resolved.
Inside Story - Will the two Sudans ever agree over Abyei?
Until then, the peace process is lying limply in the emergency room, waiting to be killed off by more conflict or possibly revived at the last minute by some diplomatic oxygen.
It was just such oxygen that pulled the two sides back from the brink of war last April, eventually leading to the Addis agreement. International alarm bells rang loudly after South Sudanese troops crossed the border and entered Sudan's main oil field, Heglig, claiming the territory as their own. The UN Security Council swiftly issued Resolution 2046, demanding the two sides pull back and start talking. Under the resolution, if they did not make a deal on all their outstanding issues within a three-month deadline - which has since been repeatedly extended - they could face sanctions.
Nearly a year later, the UN and the AU face several other pressing items on their agenda such as Mali, Congo, and upcoming elections in Kenya - meaning that the Sudans have a lot of competition.
A UN source in New York told Al Jazeera that despite these other demands, the situation in Sudan is being closely monitored. "The situation is volatile and tense and you can have escalation. But we don't believe that they have gone so far as to sign the September 27 agreement and now risk everything by going back to war. We don't believe that is what they want."
There are slivers of hope. Discussions on the ongoing rebellion along the Sudanese border in South Kordofan and Blue Nile states are due to take place on March 5. The SPLM North will meet the Sudanese government for direct talks at the AU in Addis Ababa. But their positions - publically, at least - remain far apart.
President Bashir recently reiterated his government's position that talks should only focus on the issue of South Kordofan and Blue Nile state, as outlined in the 2005 peace agreement. This is in line with the mainstream international approach in dealing with conflict in Sudan, which is to treat each matter separately, whether South Sudan, Darfur, or South Kordofan and Blue Nile states.
The SPLM North, which is now in an alliance with Darfur rebel groups under the banner of the Sudan Revolutionary Front, says there is a need for a nationwide peace agenda. Yasir Arman, the SPLM North leader, told the Sudan Tribune: "Any political solution must be comprehensive, aimed primarily at developing a national agenda with the participation of all political forces and civil society groups in order to get an answer about 'how to govern Sudan before who governs Sudan'."
Follow Harriet Martin on Twitter: @harrietinwords