The first House Armed Services hearing of the new Congress, an examination of the deployment of thousands of troops to America’s southern border, did not answer fundamental questions about the mission, now in its third month.

Most lawmakers neglected to adequately press defense officials on the contentious deployment on Tuesday, and Pentagon witnesses were unable or unwilling to answer many of the questions they got.

The need for answers grew more urgent Tuesday as acting Defense Secretary Patrick Shanahan told reporters at the Pentagon that “several thousand” more U.S. troops would be needed to fulfill a Homeland Security Department request.

President Donald Trump tapped U.S. forces for the mission in early November, and the Pentagon has authorized it to continue through at least Sept. 30. The ostensible objective is to secure the border against a wave of immigrants that the president says is composed largely of criminals.

“Why all the sudden now is it a crisis and what impact is it having on the military?” asked Washington Democrat Adam Smith, the new committee chairman, at the start of the hearing.

But even after more than two and a half hours of testimony at Tuesday’s hearing, Smith’s question — and those that follow from it — remained largely unanswered.

The list of unknowns includes: How much will it cost to maintain the current military force on the border for the rest of the fiscal year? What threat justifies this military response? What is the precise impact on the troops’ ability to perform their primary missions, which are not at the border? And why are so many active-duty troops needed, as opposed to the National Guard?

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Cost and troop numbers

The most basic questions are: How many troops are on the border, and how much is this costing?

At the hearing, John Rood, the Pentagon’s under secretary for policy, said there are just over 2,300 active-duty troops there now. But Rood never said during the hearing how many Guard and Reserve troops are present, nor did he state the sum total of military personnel deployed to the border.

Reporters were told on Tuesday that the number of Guard personnel is just under 2,300. So the total is about 4,600.

But no one ever said that at the hearing.

A similarly fractured picture emerged of the costs.

Officials said a minimum of $237 million has been spent so far on deploying both active-duty troops and Guard personnel. And an estimated $448 million would likely be spent on deployments of just Guard troops through this September, they said.

But no figure was provided, or sought, for the active-duty deployment cost or for the sum total of the cost of all the troops, active and Guard, on the border in fiscal 2019.

Based on the numbers that have been provided, though, the final price through September appears likely to be well above $1 billion at current troop levels.

And that would be for the current level of less than 5,000 soldiers. If “several thousand” more are added, the costs will only rise, perhaps significantly.

Threat

Smith pointed out Tuesday that the supposed wave of unauthorized border crossings is actually down in recent years, to about a third of the 2005 level.

Trump has said terrorists and violent criminals, including drug traffickers, have entered America across an allegedly porous southern border.

On terrorism, Vice Adm. Michael Gilday, the Joint Staff’s director of operations, testified Tuesday that “the threat is real” and offered Republican Rep. Don Bacon a classified briefing on it.

But Gilday did not say that any terrorists have been seen or caught along the southern border. No public evidence has emerged of any such activity.

A few Republicans on the committee suggested that suspected terrorists who live anywhere in Latin America could potentially cross into the United States from Mexico. But that potential concern is different from a realized threat.

The refugees amassing at the southern border comprise mostly people fleeing drug violence and poverty in Central America, and so are more desperate than dangerous, experts say.

As for drugs, they are flowing in mostly at legal border checkpoints such as ports, not at weak points along the U.S.-Mexico land border, analysts have said.

Speaking of drugs, Virginia Democrat Elaine Luria asked how many troops U.S. Southern Command has asked for but been denied as it seeks to interdict drugs in the water, air and land in and around Central America and South America.

Adm. Kurt Tidd, the Southern Command chief, testified last year that his forces are able to stop only a quarter of the drug shipments they detect due to a lack of people and assets.

Luria’s implication seemed to be that actual counter-drug missions could use some of the manpower now diverted to the border.

Gilday was not able to provide a number for how many more personnel Southern Command needs. He argued that counter-drug missions have long been starved for funds, and even more so since the Pentagon has increasingly shifted its focus to Russia and China.

But Luria’s line of questioning suggested she thinks the fact that Southern Command has long needed additional forces is not a good argument for denying them still more.

Then there is the American appetite for illegal drugs that is fueling the problem.

“It is much more of a demand problem than a supply problem,” Smith said.

Role of active troops

While previous administrations have sent more than 1,000 military personnel to the border, the large numbers of active troops in the current deployment is unusual.

Several Democrats tried to get at why. Gilday at first said the reason was “timing”— the need to promptly deploy in early November large numbers of troops with the requisite skills. Then, in answer to a subsequent question, he added a host of other reasons but acknowledged that the urgent nature of the initial call for forces was the “primary” reason for using so many active troops.

But the troops have been there for nearly three months now, and the plan is to keep them for at least seven more months. So the timeliness argument no longer holds.

Mac Thornberry of Texas, the committee’s top Republican and its former chairman, suggested to reporters after the hearing that the Guard may not be the right force because they are not full-time soldiers and they may not have all the necessary skills.

Perhaps that is the case, but the Pentagon has not made that at all clear.

Critics argue that Trump used a large number of active-duty troops to appear to be addressing a real threat in a vigorous way.

Neither Rood nor Gilday proved at Tuesday’s hearing that active-duty personnel possess more skills relevant to border security than do Guardsmen — or Army Corps of Engineers personnel, for that matter.

Mostly what troops have done is build concertina wire along scores of miles of the border. They have also helped with surveillance, engineering and more.

‘Readiness’

Several lawmakers, representing both parties, asked questions about the effect of the deployment on troops’ preparedness to perform their primary missions and what military tasks were going unperformed because of the border deployment.

Pennsylvania Democrat Chrissy Houlahan asked precisely which units have been deployed and said she wanted to see their readiness reports before and after their deployments.

Gilday said some soldiers are actually more trained for their core missions as a result of the deployment. He cited doctors and welders. But unexplored at Tuesday’s hearing was the question of exactly what percentage of the troops are more ready, instead of less.

Gilday acknowledged that there has been some effect on morale and readiness.

“There’s a cost with respect to dwell time,” he said, meaning the soldiers lost planned time off with their families, and that cannot be recovered, he said. The initial deployments took soldiers away from home at Thanksgiving and Christmas.

The Pentagon officials repeatedly said at Tuesday’s hearing that the Homeland Security Department was the source of the request for military personnel. But it was not a DHS idea. At one point Gilday conceded that the order for troops “ultimately came from the White House.”

Patrick Kelley contributed to this report.