Michela Wrong, author of a recent book on Eritrea, reflects on the differences in outlook between two nations that have made the Ethiopia-Eritrea conflict so intractable.
The intransigence of both sides exasperates negotiators
The two-hour drive between the Eritrean capital, Asmara, and the town of Keren includes what even blase locals regard as a particularly challenging stretch of road.
Built by the Italians, it zigzags down a mountainside, tracing a hair-raising route past giant boulders, deep ravines and sprays of candelabra cactus.
Torturous and twisted, the stretch is known as the "Heart of Tigray", after the neighbouring Ethiopian province that was once an ally in Eritrea's fight for independence, now the enemy.
"We Eritreans think with our hearts, but the Tigrayans are very wily, very complicated. Just like the road," any local driver is happy to explain.
The fact that ordinary Eritreans have gone so far as to baptise a road after a neighbour's perceived perfidy gives some insight into the strength of the emotions that have allowed a minor dispute over a border village to balloon into an issue that threatens to sabotage peace in the Horn of Africa.
Since Eritrea and Ethiopia first went to war in 1998 over the dusty settlement of Badme - a conflict that threatens to reignite at any moment - diplomats, international emissaries and United Nations officials have learnt to their cost how deep the hostility and suspicion runs between the two former rebel movements now ruling both states.
They have also come to appreciate, if not to savour, the character traits that make it hard for either regime to compromise, with both leaderships demonstrating what can seem a suicidal readiness to see their own communities hungry and bankrupt rather than be caught blinking first.
During the 1980s, when the Eritrean People's Liberation Front (EPLF) and Tigrayan People's Liberation Front (TPLF) combined forces against Ethiopia's Marxist dictator, Mengistu Haile Mariam, analysts dwelt on the fraternal relationship between Isaias Afewerki and Meles Zenawi, the groups' respective leaders.
The two men were undoubtedly close, but brothers can also be intensely, destructively competitive. The relationship was always a stormy one, with each side brooding over perceived slights, chafing over their enforced intimacy.
Looking back across the centuries, the Eritreans mulled over the bloody raids staged by Ras Alula, the ruthless 19th century Tigrayan warlord and slave trader who crushed any local chieftain foolish enough to stand up to his employer, Ethiopian Emperor Yohannes IV.
That historical resentment was offset by a more recent sense of cultural superiority.
Eritreans took pride in their 1890 colonisation by the Italians, a contact, they felt, that had left them better educated and more sophisticated than their neighbours to the feudal south.
That impression was furthered by the fact that after Eritrea was forcibly annexed by Ethiopia's Haile Selassie in 1962, poor Tigrayans flooded into Asmara in search of work as janitors, cleaners and labourers.
If a job was dirty and demeaning in Eritrea, it was probably done by the "Agame", as the Tigrayans were dismissively known.
Once the rebel movements came into their own, this Eritrean superiority complex acquired a military dimension.
Meles' relationship with Isaias was always a stormy one
More experienced, better-organised, battle-hardened, the EPLF boasted a far more impressive array of stolen weapons than the TPLF.
"We had to teach them how to fight. Without us, Mengistu would still be in power," former Eritrean fighters still scoff.
The TPLF, for its part, did not appreciate being given lessons in military strategy or being lectured over political ideology. Each group committed acts regarded as unforgivable by their some-time allies.
The episode in the mid 1980s when the EPLF cut the aid route to Tigray, stopping food reaching the province's starving peasants, was a particular cause for bitterness.
After the TPLF, supported by EPLF tanks, captured Addis Ababa in 1991, there was a sense the tables had turned.
Now in control of a country whose population, land mass and resources dwarfed those of tiny Eritrea, the TPLF felt it was owed gratitude for granting Eritrea independence and respect as a key player on the African stage.
Famously prickly, Mr Isaias never obliged.
Since the 1998-2000 war, in which some 90,000 died, the words "Shabia" and "Woyane" - popular terms for "EPLF" and "TPLF" - are more often spat than pronounced.
Dusty Badme was at the centre of the border dispute
With Ethiopia refusing to demarcate the border in defiance of an international boundary commission ruling, and Eritrea rejecting dialogue until its sovereignty has been formally recognised, all exchange has ground to a halt.
Outsiders who try unblocking the logjam usually depart defeated, exasperated with both players.
"Too much damn testosterone," was the succinct verdict of one American diplomat I met.
On Eritrea's side, a history of foreign meddling has given rise to an intransigence that verges at times on paranoia.
Ignored by the UN, which had promised to protect Eritrea's short-lived federation, Eritrea then fell victim to Cold War politicking, as first the United States and then the Soviet Union filled Mengistu's warehouses with arms.
Decades of superpower cynicism left the EPLF convinced foreign advice was suspect and Eritrea must go it alone, a frame of mind not suited to deal-making.
Isaias Afewerki is famously prickly
But the TPLF is hardly renowned for its pliable nature, either.
Born in a famine-prone province traditionally neglected by Addis Ababa and despised by the dominant Amhara, the group shared the EPLF's stiff-backed pride, its determination never to lose face.
Attempting to explain this mutual absence of malleability, some researchers seek explanations in the macho, isolationist culture of the highlands, the notions of absolute truth preached by the Orthodox Church and the rigidity of classic Marxist ideology.
Albanian socialism, cited by Mr Meles as his inspiration, is hardly associated with flexibility, after all.
"I don't know whether it's cultural, religious or historical. All I know is that room for manoeuvre and compromise don't seem to feature in politics in the Horn," remarks an aid worker who has worked in both areas.
"Both sides seem adept at getting themselves into a position where there is no end game."
Like the vitriolic exchanges on Eritrean and Ethiopian websites, remarkable for their bile, this is a world of black-and-white certainties, bereft of shades of grey.
Michela Wrong is the author of "I didn't do it for you: how the world betrayed a small African nation", published by Harper Perennial.