After World War I was fought on such terms, the human toll moved nations to forswear military conflict. In the Horn of Africa, however, the killing continues -- despite one side's declaration of "total victory" and the other's acceptance of a regional peace plan.

The resumption of the nine-month conflict between Ethiopia and Eritrea has been so lethal in recent weeks that when Eritrea last week claimed to have killed 10,000 Ethiopians in only three days, Western military analysts greeted the assertion with due skepticism but not with ridicule.

In fact, some analysts have estimated battlefield fatalities approaching 15,000 -- a figure equal to one-quarter of U.S. casualties during the Vietnam War.

"We don't know how exaggerated the claims are, but clearly it does appear that the casualties are extremely high, which is what you get when you combine modern weapons' firepower with tactics from the First [World] War," said Richard Cornwall of the Institute for Security Studies in South Africa.

On a continent spattered with conflicts, the war in the Horn exists on another scale. The 40,000 soldiers that diplomats say each country lined up on its side of the front at Badame and again at Tsorona nearly equaled the total number of forces -- 50,000 -- that more than a half-dozen other African nations are reported to have poured into the ongoing war over Congo. That war -- though unusual because foreign nations have intervened -- is in many ways a more typical African conflict. The units are small and highly mobile and are fighting in jungle terrain.

In contrast, the forces dug in along the 600-mile border between Ethiopia and Eritrea are fighting a conventional set-piece war. James L. Woods, the top Pentagon official for Africa in the Bush administration said Africa has not seen its like since the North African campaign of World War II, and the armies fighting then were European and American.

Both forces are huge. U.S. officials estimate that Ethiopia began the war with 250,000 troops and Eritrea with perhaps 200,000. And both are exceptionally well-armed.

The world has not yet laid eyes on the scene of the most intense fighting, the trench lines that Ethiopian troops finally breached on Feb. 26 at Badame -- the rocky, 120-square-mile triangle of disputed border land where the two countries' simmering territorial and political differences first flared into war last May. The cost of driving Eritrea out of the Badame area -- every bit as uninviting as the meaningless turf that lay between many of World War I's trench lines -- was "not inexpensive," said Tekeda Alemu, Ethiopia's vice minister of foreign affairs.

But last week Eritrean officials led foreign journalists to a second front, at Tsorona, about 50 miles from the Eritrean capital, Asmara. The scene was so devastating that Ethiopia insisted it must have been staged.

In a 200-yard stretch, reporters from Britain, Switzerland, China and other countries counted the bodies of 300 Ethiopian soldiers, some halfway into the Eritrean trenches they died assaulting. The infantry apparently approached Eritrea's heavily fortified positions on foot, either behind or beside Soviet-made tanks. Twenty such tanks lay wrecked in an area that a BBC reporter described as the size of a soccer field.

Two ruined bulldozers were also visible -- but only one armored personnel carrier, the heavily armored vehicle that modern armies rely on to protect their infantry from withering fire.

"A hell of a defeat, I'd say, for the attacking army," Woods said.

The Ethiopian government, which declared "total victory" in the war after winning the battle for Badame, questioned the authenticity of the scene at Tsorona. In a statement headlined, "Eritrea Stages Another PR Drama," Ethiopia's official government spokesman asked: "How do those reporting know that the destroyed tanks . . . belong to Ethiopia, or that the smell of rotting corpses indeed comes from dead Ethiopian soldiers?"

Eritrea's spokesman meanwhile insisted that the estimate of 10,000 Ethiopian dead was "very conservative."

"The Ethiopians used four divisions," said Yemane Gebremeskel, an adviser to Eritrean President Issaias Afwerki. "The battlefield was very narrow. We had assaults by these divisions in successive waves. And we were firing from fixed positions.

"Their tactics are suicidal," Yemane said. "It seems aimed at gaining territory at maximum cost."

The roots of the conflict lie in the rise to power of two rebel groups that combined to defeat Ethiopian dictator Mengistu Haile Mariam, whose Marxist regime received billions in arms from the Soviet Union, and then formed new governments in each country.

Much of Mengistu's arsenal was captured by the Eritrean People's Liberation Front, the rebel group now in power. The remainder fell to the new Ethiopian government, which accepted independence for the province of Eritrea in 1993. The friendly neighbors scaled down their huge military forces over the next five years.

After growing economic, political and territorial tensions erupted into war last May, however, each began shopping the international arms bazaars. Eritrea invested in small arms and MiG-29 fighter jets. By most accounts, Ethiopia spent much more, buying tanks, Su-27 fighter jets, helicopter gunships and missiles.

"This is perhaps the lesson of the Ethiopia-Eritrea war," Cornwall said. "It is possible to arm yourself to the teeth relatively cheaply, with all the stuff coming out of the former Soviet empire -- plus whatever China and the others decide to throw in. You can buy yourself a T-55 tank for $50,000."

Analysts say the new equipment is boosting death tolls already inflated by the low level of battlefront medical care. What's unclear is which side is benefiting.

As U.S. forces demonstrated in the Persian Gulf War, modern weapons can dramatically reduce the vulnerability of an attacking force. And in the Horn war, Ethiopia, which bought most of the new gear, is believed to be attacking. But without sufficient training -- and without adopting tactics that coordinate troop movements with the advanced weaponry -- what Eritrea's Issaias derisively calls "new toys" might backfire, analysts say.

"Mobile warfare, combined-arms warfare is not easily waged," Cornwall said. "It has to be very finely tuned to go forward without suffering huge casualties."

In taking Badame, the largest stretch of disputed territory, Ethiopian forces succeeded in combining fire from artillery, armor and aircraft on a specific point, according to a Western military analyst in Addis Ababa, the Ethiopian capital. "They took out a defense that the Eritreans took eight months to build," said the analyst, who asked not to be named.

Despite the toll incurred on the advancing Ethiopians, the losses for Eritrea were devastating, according to two military analysts, who described how assaulting Ethiopian forces broke through at two points on the Eritrean line, then "policed" the 1 1/4-mile stretch of trenches between the breach points.

The analysts estimated 3,000 Eritrean fatalities, a loss that, for a nation of 3 million people, would be comparable to an American battlefield loss of 270,000 lives. But in Asmara, the talk is of the emotional toll the war is taking on Eritrean troops who survive with the memory of hour after hour spent gunning down young Ethiopians scrambling toward them across open ground.

No one expected otherwise. Diplomats who worked for nine months to find a negotiated settlement said their efforts were fueled by visions of the horrific battles a trench war would bring. Ethiopian Prime Minister Meles Zenawi has pointedly observed that the larger country should prevail because it can bring more "resources" to the battlefront. Ethiopia has 60 million people.

"The question is, when does the personal cost become too much to pay?" said Woods. "I'm a little skeptical that military losses have hit 10,000 yet. But they will at this rate."