The Pentagon said no.
According to two defense lawyers familiar with the application, the Department of Homeland Security called on the Pentagon to set up a reserve force that could be called upon to provide "human and traffic control" and border customs and border guards against a group protect Central American migrants who go to the US border to apply for asylum.
The Pentagon rejected the request on October 26, one of the officials said, even as it supported the DHS with air and logistics support, medical personnel, and engineers.
The request was rejected because the Ministry of Defense considered that active troops are not authorized to carry out this type of mission unless they are given additional powers by the President.
Defense officials have repeatedly stressed that the troops at the border are there to assist the civilian authorities and that they would not be expected to come into contact with migrants.
Although several defense officials described these activities as law enforcement actions, one DHS representative considered these functions to be criminal prosecution.
"Although the DHS has discussed the need for potential assistance in the protection of CBP personnel using coercive measures, it would be in fact inappropriate to refer to this support line as" law enforcement activities, "the DHS official said.
& # 39; Fast and for a long time & # 39;
In a speech in the White House on Thursday, the president suggested that troops should shoot at migrants when they throw stones, and that stones should be considered rifles, and the group of about 3,000 men, women, and children with them compared to an "invasion".
On Friday, Trump tried to reject these comments and tell reporters that "if our soldiers or border or immigration and customs officials" are hit with stones in the face, we'll arrest those people, which does not mean they shoot them. But we will arrest these people quickly and for a long time. "
Defense officials described the force requested by the DHS as something that could only be used if CPB personnel were overwhelmed by the border situation.
Nonetheless, the Pentagon rejected the request for the Reserve Protectorate and at the same time approved all other requests for assistance from the DHS, with the approval of US Secretary of Defense James Mattis. It is not clear whether Mattis has weighed in on the decision to reject the call of the troops to carry out law enforcement duties.
The first defense official said the Department of Defense said in its response to the DHS that if Homeland Security officials still want US forces to reserve, they should ask the White House to give the Pentagon power to perform these additional functions ,
Customs and Border Protection declined to comment.
Homeland Security Secretary Kirstjen Nielsen said a week ago with Fox News that the DHS was asking about aviation, engineering, logistics and planning support, as well as vehicle barriers and ways in which we could protect my officers and agents as well as the ports themselves. "
The Posse Comitatus Act prohibits the US military from enforcing domestic laws unless there is no other choice. Military analysts said Trump could easily use the National Guard, US Marshals or Immigration and Customs Enforcement staff to assist border guards when needed.
Cost of the operation
More than 8,000 active troops could be stationed at the south-west border, more than it has deployed in some of the world's most controversial combat zones, but they are designed exclusively to assist state security officials in preparing for the arrival of migrants.
Retired General Martin Dempsey, who was Chief of Joint Chiefs of Staff from 2011 to 2015, tweeted on Friday, "Our men and women in uniform are better educated, better equipped and better at addressing every threat to face them with self-confidence Wasteful use of overstretched soldiers and marines would be even worse if they use force that is disproportionate to the threat they face.
The Pentagon has not yet determined the cost of the operation, and it has not yet determined which account the funding would come from. The Center for Strategic and Budgetary Assessments estimates that the cost of deploying active troops at the border could range from $ 42 to $ 110 million.
According to the CSBA, the upper-level deployment would cost $ 143 per day for operating and maintenance costs and $ 112 per day at the low end. CSBA also estimates that the use of military aircraft in this operation would cost about $ 136,645 per day.
Since the mission is currently scheduled for a total of 41 days from 5 to 15 December, the cost of deploying 8,000 troops and providing air support is between about $ 42 and $ 55 million, according to the CSBA estimate.
On Thursday, Trump claimed that the military is deploying thousands of tents to keep migrants, but officials said there are currently no plans to build tents. Officials said that although informal talks between the Ministry of Defense and the DHS were underway to establish military camps to house imprisoned migrants, tents were never part of the formal request for support submitted by the DHS and approved by Defense Secretary Jim Mattis. An official says that the DHS was informally prevented from filing the defense department's request.
CLARIFICATION: This story has been updated to highlight that Defense Department officials consider the application to be the role of law enforcement agencies. The Department of Homeland Security denies this characterization and the story has been updated with DHS comment.