Deploying the National Guard overseas on the basis of an Executive Order?

NBC News reports

“President Barack Obama is expected to issue an executive order Thursday paving the way for the deployment of National Guard forces to Liberia to help contain the Ebola outbreak there, sources told NBC News.

The sources said that eight engineers and logistical specialists from the Guard, both active-duty and reservists, would probably be included in the first deployment. They are expected to help build 17 Ebola treatment centers, with 100 beds apiece. The sources said that no decision had been made.

Defense Department officials said that the executive order was necessary to speed the deployments, and would allow the president to send additional forces as needed. Health officials have recorded more than 2,400 Ebola deaths in Liberia, the highest of any country.”

The National Guard? There have undoubtedly been numerous changes for the worse in our laws in recent years, but when did the President get the authority to call up National Guardsmen for duty beyond our borders on his own imperial say so?

What the hell has this country, and have its people, become?

UPDATE:

In partial answer to my own question we have this from the Heritage Foundation. I have made paragraphs in some cases where none were before in order to emphasize certain points.:

“In the 1980s, governors again resisted a presidential call for the militia (National Guard). Some of them objected to the deployment of their states’ National Guard troops to Central America. Led by Minnesota governor Rudy Perpich, these governors withheld their consent to federally ordered National Guard active duty training, as was their prerogative under then current federal law.

In response, Congress enacted the Montgomery Amendment, which prohibited governors from withholding consent for National Guard active duty service outside the United States.

Perpich filed suit against the Department of Defense, arguing that the Montgomery Amendment was unconstitutional because it infringed on the militia training authority granted to the states under Article I, Section 8, Clause 16.

Perpich also sought to enjoin the use of Minnesota National Guard troops in any training outside the United States that did not have the governor’s consent. Ultimately, the Supreme Court upheld the supremacy of presidential control over the operations of the militia when called into actual service of the United States.

Like James Monroe and Justice Joseph Story, the Court held that a state governor could not veto the use of a state militia when called upon by the nation in accordance with Congress’s constitutional power and the President’s constitutional authority.

Recent Presidents have made more use of the National Guard as a reserve, calling units up for long periods of duty abroad, in actions in the two Gulf Wars, Bosnia, and Afghanistan.”

All this still leaves open the matter of Congressional assent, and under what legal authority the militia is being “called into the actual service of the United States”.

My, what a race of serfs we have become.