By Jeremy Clarke and Alex Dziadosz
JUBA/KHARTOUM (Reuters) - When north and south Sudan split into separate countries on July 9, their capitals will already be worlds apart.
The north's Khartoum feels secure and ordered, but riven with anxiety about what will happen after the departure of the oil-producing south. About 1,200 km (750 miles) away, the southern boomtown Juba is lawless and chaotic, but buoyant with optimism about its future.
The sharp inequality between the relative development of the north, at least in its cities, and the impoverished south was one of the grievances that drove southern rebels in decades of civil war against Khartoum.
Juba's dusty streets, in contrast to Khartoum's eight-lane Chinese-built highways, highlight how far the south still needs to go in its efforts to build a nation essentially from scratch.
Southerners chose to secede in a January vote promised in a 2005 peace deal that ended the north/south civil war.
A mishmash of former rebels is now charged with policing the south, roughly the size of France. Most lack formal police training, and a dearth of powerful institutions means the state's writ often ends where the barrel of an officer's gun begins.
"What are you doing? It's after midnight -- it's our time. Only criminals are still out, are you a criminal?" one soldier shouted, ripping the key from a Reuters reporter's motorbike last week. Rumors of far worse treatment meted out to locals are all too common.
New police uniforms and cars give the force a veneer of order, but the country-in-waiting still lacks clear laws. Journalists, for instance, are often harassed while they wait for a long-promised media bill.
The legal vacuum fosters an air of hedonism unthinkable in Khartoum. Cars zip down dirt roads without concern for speed limits and residents swig Kenyan lagers openly in outdoor cafes.
In the north, even the water pipes that used to bubble in roadside cafes were outlawed this year. Drinking heavily sugared tea is about the biggest vice commonly accepted in public.
Many northerners are nervous about the ubiquitous secret police, refusing to talk politics over the phone. Unlike the localized chaos of the south, in the north the fear is rooted in broader conspiracies, of power concentrated in unseen hands.
"WORLD'S BIGGEST VILLAGE"
A ride through Juba's potholed streets and muddy lanes shows how much work remains to be done in what will be considered one of the world's least-developed countries.
There are few buildings higher than two stories in the sprawling city, clearly expanding as hundreds of thousands of southerners flock back from the north and abroad.
Many hotels use tents or pre-fabs instead of investing in permanent structures. Inhabitants call it the "world's biggest village" -- some affectionately, others derisively.
Construction work is uncontrolled. Huge, unmarked holes are dug and left for days on central streets.
Government meetings are often interrupted by electricity blackouts. Unreliable diesel generators power the city in the absence of any national grid. Many southern officials have two or three phone numbers because of unreliable mobile networks.
Such challenges lead many in Khartoum to see the south as a desolate place, its sole advantage the relative freedom. "You can drink beer in Juba, but that's all," one northerner said.
Seated at the confluence of the Blue and White Niles, Khartoum still has plenty of dirt roads and snarling traffic, but for the most part traffic lights stay on and drivers obey them.
Along the Nile, a smattering of self-consciously modern glass and steel towers and British colonial-era red brick compounds now housing ministries and museums give the city an air of history and wealth lacking in its southern counterpart.
Outside downtown's grid-like layout -- it is said the city's former British masters modeled it to resemble the Union Jack -- designer restaurants and cafes catering to wealthy Sudanese and foreign workers have sprouted up in droves.
The two capitals are often distinguished by their "Arab" and "African" characters, but such generalizations deny the complexity and diversity of both.
Underneath the surface there are plenty of similarities that suggest the two will stay to some extent socially and economically interwoven even after the split becomes official.
Both cities are relatively new, with roots as military garrisons and trading posts set up by the invading Turkish-Egyptian army in the 19th century. In both, Arabic is the unifying language used across a cosmopolitan array of tribes and ethnicities.
Oil is the lifeblood of both economies and their industries are deeply intertwined. Most of the fields are in the south but nearly all the ports, refineries and pipelines are in the north.
Both also face widespread complaints of corruption. The north's local media became increasingly vocal in criticizing the routine nature of graft after anti-government revolts in neighboring North African countries.
In Juba, corruption reared its head as guerrilla fighters took over a government with almost $2 billion a year at its disposal.
On the town's main new road, massive buildings have emerged which at first glimpse could be the south's ministries. In fact they are the homes of ministers, many of whom zoom along the road in shining new 4x4s or even Hummers.
Locals curse the cars as they power down the unofficial "government lane" which runs through the middle of Juba's streets.
(Writing by Alex Dziadosz; Editing by Andrew Heavens)