By Maggie Fick
NAIROBI (Reuters) - Once again, troops are rushing into a rugged corner of Ethiopia that has been at the heart of momentous events for decades, from war with Eritrea to the toppling of a Marxist dictatorship.
This time, it is the federal government sending jets and soldiers against the restive northern Tigray region in an offensive with ethnic undertones that threatens to destabilise both Ethiopia and the wider Horn of Africa.
Reuters reporters in the area this week saw trucks full of militia fighters and pickups with machine-guns rushing along windy mountain tracks to the front line in support of federal troops' offensive against Tigrayan forces.
Helicopters flew overhead and some villages were deserted.
Conflict and hardship are nothing new to Tigrayans.
They were the leading force among rebels who wrested power from the brutal Marxist Derg regime in 1991.
They also bore the brunt of a horrific 1998-2000 conflict with Eritrea that saw tens of thousands die in battles over scrubland that drew comparisons with the attrition and trench warfare of World War One.
Though accounting for just 5% of the population, Tigrayans dominated politics and the military from 1991 until Prime Minister Abiy Ahmed - an ethnic Oromo - took office in 2018.
Their tight grip brought repression of alternative views but also sustained economic growth in a nation that had become a byword for poverty in the West, establishing Ethiopia as a regional powerhouse.
Even though Abiy had been a minister and head of a security agency in that government, as premier he condemned past rights abuses and had many leading Tigrayans detained or sidelined.
When he merged the ruling coalition into one party last year, Tigray's political party - the Tigray People's Liberation Front (TPLF) - refused to join and accused him of undermining the constitution, which enshrines a system of ethnic federalism.
In September, Tigray defied Abiy to hold a regional election after the government postponed voting nationwide due to the COVID-19 pandemic. Tigray's poll was declared illegal and its budget cut.
Then last week, Abiy accused the TPLF of attacking a federal military base and launched his offensive.
HISTORY OF RESISTANCE
The history of guerrilla resistance looms large in a society that used its highland terrain and foreign borders to its advantage through years of armed struggle in the 1980s.
Fighters, both men and women, marched with AK-47s on their back and some with plastic sandals on their feet, to the capital Addis Ababa, 1,000 km (620 miles) south in 1991 to overthrow Mengistu Haile Mariam's "Red Terror" regime.
A museum in Tigray's capital Mekelle recounts the bravery of the "martyrs" and local TV still shows footage of the march.
Though Tigray has modern roads and several airports - an indication of the group's dominance before Abiy - many of its people remain poor. About 600,000 depend on food aid to survive.
The central bank has ordered all banks in Tigray closed.
Abiy appears bent on crushing the local leadership, diplomats say, but that is no easy task.
Tigrayan forces and militia are battle-hardened, have large stocks of military hardware and number up to 250,000 men, experts say. Federal authorities have restricted access to the region, making it hard to verify details of the fighting.
However, there are indications that Tigrayans in the powerful Northern Command, which accounts for about half of the federal army's manpower and its best divisions, are defecting.
Local forces are already in control of its headquarters in Mekelle and other army facilities in Tigray, according to a United Nations internal security report seen by Reuters.
Ethiopia expert Alex de Waal said Abiy may have underestimated the Tigray leaders' skills at both politics and war.
The Tufts University academic recalled the words of Tsadkan Gebretensae, a Tigrayan who once commanded Ethiopia's army against Eritrea, in a conversation with him: "War is primarily an intellectual activity."
(Reporting and writing by Maggie Fick; Editing by Andrew Cawthorne)