King Abdullah II of Jordan is meeting with President Barack Obama at the White House on Wednesday, for working talks that the Jordanian Embassy describes as covering "the strategic partnership" between the two countries. In addition to discussing the flood of Syrian refugees into Jordan — there are now 750,000 of them — the Embassy also says that the two will "tackle global efforts to combat terrorism and extremism across the Middle East, Africa, and the world." The White House mentions the talks in the president's daily schedule, noting the two will discuss "efforts to counter ISIL (and) resolve the Syrian conflict," using the US government's favorite acronym for the Islamic State group.

But that's a very reductive description of what the monarch and the president are likely to talk about. There's a major war going on across the Hashemite Kingdom's northern and eastern border, and much about Jordan's military role in that war won't likely be the subject of press releases. But the border is undoubtedly somewhere buried in the briefing books. The Obama administration is spending close to a half a billion dollars to build a sophisticated electronic fence along Jordan's northern and eastern borders, a wall which US strategic planners hope will stem the flow of refugees and also wall off the increasingly important American base from the disintegration of Syria and Iraq.

The wall, which began as a $20 million project in 2008 to erect a set of surveillance towers along a 30-mile (50 km) stretch of the border with Syria, has since expanded into a program costing half a billion dollars, according to defense officials who spoke to VICE News. Called the Jordan Border Security Program or JBSP, the wall is ostensibly meant to stop weapons of mass destruction from getting out, but since 2013 has refocused on detecting Islamic State fighters and arms smuggling, as well as refugees, on both sides of the border.

When completed later this decade, the border wall will have a camera-studded high-security fence, plus a network of ground sensors and a set of fixed and mobile surveillance towers that will be able to see and detect activity five miles away on either side of the fence. The entire system funnels into a joint US-Jordanian command center, where the United States also shares additional intelligence with Jordan about external threats to the kingdom.

The first phase of the JBSP, the erection of the towers, was completed in September 2009. Phase 1B, the beginning of the fence, was completed in March 2014. Phases 2 and 3, the building of a fully integrated and networked fence running along a 275-mile(442 km) stretch of Jordan's borders with Syria and Iraq and costing some $300 million, are scheduled to be fully operational this year. Further phases will extend the fence along the entire border and improve surveillance and detection gear. Mobile surveillance stations and quick reaction forces will be stationed at vulnerable points or emerging hot spots.

It's all paid for by the United States taxpayer. The JBSP is loosely part of a wall-building program to stop weapons of mass destruction sponsored by the Defense Threat Reduction Agency, focused not just on Jordan but also on the borders of Turkey, Iraq, and Lebanon. Raytheon Intelligence, Information and Services of Tucson, Arizona, a division of the Raytheon Company — one of the largest US defence companies — is the prime contractor.

Kenneth A. Myers III, who heads the United States Center for Combating Weapons of Mass Destruction, told Congress last year that "the system is designed to detect a person from five miles away and provides the Jordanians with a capability to safely detect, inspect, and apprehend someone suspected of smuggling WMD," he said.

If you've never heard about the Jordan wall, it is because — despite its position at the physical center of the US war with the Islamic State group — the official position of the Jordanian government is that there are no US troops in the country, much less US military bases.

Yet since the low point of 1991, when then-King Hussein opposed the first Gulf War, US-Jordanian military and intelligence relations have flourished. That cooperation grew in the 1990s as the Iraqi population and Iraqi commerce grew in Jordan, which enjoyed normal relations with the neighboring Baghdad government.

During the more than a decade of low-level American war against Saddam Hussein until the invasion of 2003, Iraqi refugees, businessmen and defectors who set up shop in Amman were exploited and recruited by the US, and the capital Amman became a hub for operations against the Iraqi regime.

After the 9/11 attacks, the United States increased funding and technical support for Jordan's General Intelligence Directorate. The US established signals intelligence monitoring stations in Jordan, listening in on Iraq, and then in the run-up to the Second Gulf War sent warplanes to bases in Jordan and deployed a special operations team to attack Iraq from the west. King Hussein's son, Abdullah II, himself a former commander of Jordan's special operations force, has been instrumental in making these military and intelligence ties ever closer; in exchange, the US has provided funding for the creation of the King Abdullah Special Operations Training Center, a multinational hub supporting the fight against Islamic State.

Jordan was also directly instrumental in much of the post-9/11 hunt for high level al Qaeda targets, especially Abu Musab al-Zarqawi in Iraq, and there have been consistent and reliable reports that Jordanian secret services and intelligence personnel have done "dirty work" for their American counterparts, including interrogations, targeted killings, and even torture of suspects. Jordan has been a hub for extraordinary "renditions" of high value terrorist suspects. In April 2002, it sent a special forces unit to Yemen to work with the United States in training and assisting the Yemeni military to fight al Qaeda.

The ultimate reward for this effort came in 2008, when the US and Jordan signed a memorandum of understanding to provide assistance to Jordan over a 5-year period. In 2013 and 2014, the US provided Jordan $2.25 billion in loan guarantees, allowing the government access to affordable financing from international capital markets. And in February 2014, President Obama announced that the United States would renew the memorandum.

President Barack Obama meets with King Abdullah II in the Oval Office at the White House in December 2014. Photo by Kevin Dietsch / EPA/ Pool

According to the Defense Manpower Data Center, the United States has 56 personnel in Jordan — 42 military, three civilians, and 11 dependents, a number whose modesty pleases a host country that would like it a secret for internal reasons. But a true accounting is closer to 12,000, a number that demands that one drill far down into a byzantine secret structure to sort it all out. According to US military documents, there are 3,300 openly deployed "Title 10" military forces in the country — that is, those who are there to provide training. The Embassy itself and the foreign military sales apparatus that supports American equipment owned by the Jordanian armed forces (the air force, for example, flies American-made F-16 fighters in its airstrikes against the Islamic State) include almost 1,000 soldiers, spies, administrators and contractors. Another 1,000 contractors paid by Washington are working on the wall and other construction projects in the country. None of these obviously identified Americans are accounted as being in the country because they aren't officially "based" in Jordan, just "deployed."

As for the war against the Islamic State (IS), known as Operation Inherent Resolve, both countries are silent on the combat deployments. Multiple headquarters have been set up inside Jordan for US and coalition forces, including US Central Command Forward – Jordan, an entity known as CFJ which links together the 40-country planning team. Another command is the Combined Joint Operations Command Jordan or CJOC-J, which oversees the "Title 10" forces. The Army's 513th Military Intelligence Brigade sits alongside Jordanian counterparts monitoring and exchanging intelligence at the King Abdullah Special Operations Training Center. In addition to the latter, there is also a Joint Training Center – Jordan, with US Army and Marine mentors. The Ground Intelligence Center in Amman is the central hub of the war-related intelligence exchanges.

Inside Jordan, Special Operation Command Central operates its own task forces and remote bases, as do the "black" forces of Joint Special Operations Command and the CIA. Naval special warfare personnel work with their Jordanian counterparts on Operation Gallant Phoenix to secure the southern ports and waters. US naval intelligence is supporting the Kingdom of Jordan Maritime Surveillance System, a sea-based protection system to the south.

The American presence, though obviously known to Jordanian residents and local spies, goes on in the shadows. But this is not the case when it comes to military cooperation that predates the IS war. The Jordanian air force units flying F-16s carry out public exchanges with the 162nd Fighter Wing in Tucson, Arizona. The US and Jordan have an active — and mostly public — program of joint exercises that has been going on since 1993, taking place every year, and American ships pay regular visits to the Red Sea port of Aqaba, Jordan's only outlet to the sea.

US and Jordanian soldiers during joint training. Photo by US Department of Defense

The new anti-IS wall and its guardians, in short, are nothing new in Jordan, whatever the official Jordanian statements say.