As the world is transfixed by the tragedy playing out in Afghanistan, another humanitarian catastrophe is getting little scrutiny.

In Ethiopia, a conflict with roots in a dispute between the central government of Prime Minister Abiy Ahmed and authorities of the northern Tigray region has spilled into neighboring provinces and metastasized into a full-blown civil war — one fueled as much by ethnic enmities as by political grievances. It’s time for the West to pay attention and get tougher on the government in Addis Ababa.

International rights groups are seeing an all-too-familiar pattern repeat itself in Ethiopia: There’s the weaponization of rape and hunger, the use of child soldiers, reports of ethnic cleansing and warnings of genocide. The death toll from the fighting is thought to be in the tens of thousands, and millions have been displaced.

Worse is to come: Hundreds of thousands of Ethiopians face famine, according to United Nations agencies. The fighting is preventing food aid from reaching people in the greatest need. Abiy, a Nobel Peace laureate, has ignored appeals from the international community to halt the fighting. With the Tigray People’s Liberation Front having inflicted a series of defeats on government forces, the prime minister has called on civilians to join the army and militias, stoking fears of a wider conflagration.

Inevitably, the crisis has resurrected memories of Ethiopia’s previous experience with famine. In the 1980s, an estimated 1 million people died from starvation and malnutrition. Comparisons are also being drawn to Africa’s other cataclysmic ethnic conflicts, including the Rwandan genocide.

Ethiopia is Africa’s second-most populous nation and was, until the civil war broke out last fall, held up as a beacon for the rest of the continent: Its recent economic success was cited by investors and aid donors alike as an example for other developing countries.

That success is now imperiled as the conflict exacts a heavy toll on the economy. The risk premium on Ethiopia’s dollar debt has almost doubled this year. The ardor of investors has cooled with the government’s pleas for a debt restructuring. As Bloomberg News has pointed out, the premium demanded to hold Ethiopia’s 2024 Eurobonds instead of U.S. Treasuries has climbed to 987 basis points, the highest in Africa after Zambia, which is in default. The average spread for African dollar bonds is 541 basis points.

And yet neither economic nor humanitarian considerations carry much weight with Abiy. The prime minister seems to have taken an election triumph in June — his party won a large majority in parliament — as an endorsement of his no-compromise posture in the war against the Tigrayans.

But the conflict has grown more complicated since then. Insurgents from the Oromo, Ethiopia’s largest ethnic group, have formed an alliance with the Tigrayans against the government.

Who can stop Ethiopia from the coming catastrophe? The African Union is too beholden to the government, which provides its headquarters in Addis Ababa, to have much sway over Abiy, and it doesn’t inspire trust among the rebels. The UN’s pleas for a ceasefire have gone unheeded by both sides.

The Biden administration, on the other hand, has some leverage. Ethiopia is sub-Saharan Africa’s largest recipient of American foreign aid, amounting to about $1 billion last year. The European Union is another significant donor and trading partner. Some U.S. and EU assistance has been suspended or postponed, but this has not had any restraining effect on Abiy, who refused even to meet with USAID chief Samantha Power when she visited Addis Ababa last month.

Just in case Joe Biden missed this demonstration of defiance, Abiy also snubbed the U.S. special envoy to the Horn of Africa, Jeffrey Feltman, who flew to the Ethiopian capital the following week.

With shuttle-diplomacy and mild financial restrictions having failed, Western governments will need to lean more heavily on the prime minister to pause the fighting and allow humanitarian supplies into the war zone. The Biden administration can lead the way by suspending all nonessential aid to Addis Ababa, as well as blocking assistance from the World Bank and the International Monetary Fund. Washington should also follow through on its threat to cancel duty-free access for Ethiopian exports to the U.S. market under the African Growth and Opportunity Act.

Having already announced some restrictions on visas for Ethiopian government and military officials involved in “perpetrating the conflict,” U.S. Secretary of State Antony Blinken should now impose harsher sanctions, including freezing any assets these officials hold in the U.S., and pressing the Europeans to do likewise.

Anticipating a ratcheting up of Western pressure, Abiy is seeking support elsewhere: He got some from Turkish President Recep Tayyip Erdogan on a visit to Ankara earlier this month. But the combined clout of the U.S. and Europe remains substantial, and it should now be deployed to save millions of Ethiopians from calamity.