In early January 2010, Bob Livingston, a former chairman of the appropriations committee in the US House of Representatives, flew to Cairo accompanied by William Miner, one of his staff. The two men were granted meetings with US Ambassador Margaret Scobey, as well as Major General FC "Pink" Williams, the defence attaché and director of the US Office of Military Cooperation in Egypt. Livingston and Miner were lobbyists employed by the government of Egypt, helping them to open doors to senior officers in the US government. Records of their meetings, required under law, were recently published by the Sunlight Foundation, a Washington, DC watchdog group.

Although the names of those who attended the meetings have to be made public, the details of what was discussed are confidential. I called Miner to ask him about their meetings, but he referred me to Karim Haggag, the spokesman for the Egyptian embassy in Washington, who did not respond. Miner did confirm that he was a retired Navy pilot who had worked for clients like the Egyptian government, as well as several military contractors.

The cozy relationship between the lobbyists, members of the US Congress, Pentagon officials and the Egyptian government is easily explained: much is at stake. Egypt has received over $70bn in economic and military aid approved by the US Congress in the past 60 years, according to numbers compiled by the Congressional Research Service. Maj Gen Williams is the man in charge of the $1.3bn in annual US military aid supplied to the country.

Specifically, the aid money pays for US-designed Abrams tanks assembled in suburban Cairo under contract with General Dynamics. Boeing sells Egypt CH-47 Chinook transport helicopters, Lockheed Martin sells F-16s, Sikorsky Aircraft sells Black Hawk helicopters. Lockheed Martin has taken in $3.8bn from Egypt in the last few years; General Dynamics $2.5bn; Boeing $1.7bn; among many others.

In addition, hundreds of Egyptian military officers come for short training courses to the US each year. Two days after Livingston and Miner met with the US officials in Cairo, the embassy sent a cable to Washington with a list of Egyptian officials approved to take a three-week military training course in the US in February 2010. Under the "Leahy law" – a human rights requirement named after Senator Patrick Leahy of Vermont that prohibits US military assistance to foreign military units that violate human rights – the embassy must, as a matter of routine, vouch for the prospective trainees.

One of the training courses listed in the cable made public by WikiLeaks was listed as one in how to handle explosives. The WikiLeaks cables show that numerous officials working for "state security", aged between 30 and 50 with ranks from major to lieutenant colonel, were given clean bills of health to take a variety of such specialised military training programmes.

After the US lobbyists returned to their offices in Washington, DC, Miner kept in touch with "Pink" Williams, corresponding via email. A little over three months later, an Egyptian military delegation led by Major General Mohamed Said Elassar, assistant to Mohammed Hussein Tantawi, the Egyptian minister of defence, came to Washington. Livingstone and Miner were on hand once again to take the Egyptian officials to meet with a number of members of Congress, as well to visit the office of the secretary of defence to discuss "US/Egyptian security issues".

So, when protesters in Cairo last week were struck by tear gas canisters fired by Egyptian security officials, it was not surprising that pictures taken by ABC TV would show that the canisters were manufactured in the US. Nor does it seem that surprising that a journalist from the Sydney Morning Herald would find 12-gauge shotgun shells with ''MADE IN USA'' stamped on their brass heads when he visited the wounded in a makeshift casualty ward in a tiny mosque behind Tahrir (Liberation) Square.

The photographs show that the tear gas comes from a company named Combined Systems Inc (CSI), which describes itself as a "tactical weapons company" and is based in Jamestown, Pennsylvania. A similar picture from the protests in Egypt was posted on Twitter of a "Outdoor 52 Series Large Grenade" grenade made by CSI, which is designed to discharge "a high volume of smoke and chemical agent through multiple emission ports". (CSI did not return calls for comment.)

Although CSI markets these products as "less-than-lethal", several incidents indicate that they can cause injury and death. Bassem Abu Rahmah, a Palestinian man, was reportedly killed on 17 April 2009, when a CSI 40mm model 4431 powder barricade penetrating tear gas grenade struck him in the chest, according to a report by the Israeli human rights group B'Tselem. Nels Cooper Brannan , a US marine deployed to Fallujah, Iraq, unsuccessfully sued CSI for injuries caused by an allegedly defective MK 141 flashbang grenade that caused serious damage to his left hand when it exploded accidently.

While the Egyptian protesters were facing tear gas grenades fired by security forces in Cairo, another delegation of Egyptian senior military officials led by Lieutenant General Sami Hafez Enan, the chief of staff of Egypt's armed forces, was back in Washington to meet with Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff. (No public records have been filed yet, so it is unclear if Miner and Livingstone were escorting them again.)

Within hours of the news of the huge protests, Enan cut short his trip and dashed back to Cairo last Friday, but his boss, Minister Tantawi, has kept in touch with Washington, making daily phone calls to US Defence Secretary Robert Gates. Both men – together with Egypt's spy chief, Omar Suleiman – are among President Hosni Mubarak's closest allies and enjoy close ties with Washington, according to the diplomatic cables published by WikiLeaks. And it was these men that Thomas E Donilon, the US national security adviser, was frantically phoning last weekend to try to gauge how to prevent the collapse of the Mubarak regime.

It could days, maybe even weeks, before the future of the Egyptian government is decided, and with it, the relationship with the US. But one thing is clear: the Egyptian protesters are well aware of the close ties between officials in Cairo and Washington and not happy about the US training and tear gas shells supplied to the Egyptian military. Crowds gathered in Liberation Square last week chanted: "Hosni Mubarak, Omar Suleiman, both of you are agents of the Americans." The protesters believe that the billions in military aid that kept Mubarak in power have helped him keep democracy from flowering in Egypt.

Two years after Obama's famous speech in Cairo, in which he called for a "new beginning between the United States and Muslims", it might be a little late for his administration to heed the words of Mostafa Amin, Egypt's most famous columnist and journalist: