Egypt's government announced on Monday criminal charges against 19 Americans affiliated with pro-democracy organizations, escalating a dispute that is putting an immense strain on Egyptian-America relations.

Egyptian officials said they intended to try 43 people for violating a law against foreign organizations operating in Egypt without explicit permission from the government. The accusations intensified a confrontation between the Egyptian and American governments and provoked rising fury from the White House and Congress, who believe the Egyptian authorities are engaging in a witch hunt.

The standoff threatens to unravel a decades-old relationship between the two countries. The United States has viewed Egypt as a mainstay of regional stability given its peace treaty with Israel and has lavished it with billions of dollars in aid over the years.

But lawmakers concerned about continuing abuses by the military regime made the $1.55 billion budgeted for 2012 contingent on proof that Egypt's government is taking concrete steps towards openness and democracy. President Barack Obama and members of Congress had warned the leader of Egypt's military government that the ongoing investigation of NGOs, which included raids on their offices, was endangering this year's aid package. The charges unveiled Monday increased the likelihood Egypt would be cut off.

The likelihood of the aid being cut in some way or delayed has been increasing by the day almost, said Steve McInerney, executive director of the Project on Middle East Democracy. Unfortunately, the actions we've seen from the Egyptian government military have indicated an escalation rather than a backing down.

Three of the four accused NGOs have ties to the American government. The International Republican Institute and the National Democratic Institute were created by Congress and are financed through the National Endowment for Democracy, while Freedom House receives a substantial amount of government funding. Sam LaHood, the son of Secretary of Transportation Ray LaHood, works for the International Republican Institute.

While those connections have made Egypt's actions deeply provocative to American officials, they have also bolstered Egypt's official narrative that the groups are foreign actors meddling in Egyptian affairs. For months, Egyptian state run media have sought to portray the groups as attempting to undermine the revolution, McInerney said.

I think the administration underestimated the seriousness in previous months, McInerney said. There were lots of signs these raids and charges were coming.

There is nothing particularly controversial about the work the organizations are undertaking. The International Republican Institute and the National Democratic Institute instruct Egyptians on political organizing and elections, Freedom House trains young activists and the International Center for Journalists attempts to foster a free press.

But Charles Dunne, the director of Middle East and North Africa programs at Freedom House and one of the Americans facing charges, described an unprecedented campaign in the press to vilify and demonize everyone who is working for an international NGO or working with them.

We expected that after the uprising in Egypt that overthrew [former president Hosni] Mubarak the operational environment would become much easier but in fact it's become much more difficult, Dunne said in an interview with Public Radio International.

Dunne added that organizations like Freedom House often operate in legally murky territory when trying to work with hostile foreign governments. Faced with a dense bureaucracy and murky regulations, some American organizations were working on the limits of legality and were thereby vulnerable to a crackdown, according to Marina Ottoway, a senior associate at the Middle East program of the Carnegie Endowment for International Peace.

The Egyptian government, for its part it became a question of nationalism more than anything, Ottoway said. I don't see how they could have been feeling threatened by the nature of these activities but they saw them as interfering, as an expression of American arrogance essentially.

The charges come at a time of mounting civil unrest and popular outrage at the abuses of Egypt's military rulers. Despite Mubarak's ouster, much of the power structure he presided over remains intact. That includes the Supreme Council of the Armed Forces, who have become the de facto ruling regime, and Fayza Abul Naga, a minister of planning and international cooperation whose efforts to crack down on foreign-backed organizations stretch from the Mubarak era to the current inquiry.

For some, the Supreme Council of the Armed Forces' support of Naga's efforts illustrates the regime's increasingly repressive turn. The ruling generals have violently suppressed popular protests and have been slow to relinquish power to a civilian government.

I think this shows a sense of impunity or hubris that the SCAF has at this point, said Mara Revkin assistant director of the Atlantic Council's Rafik Hariri Center for the Middle East. I think they're just out of touch with Egyptian public opinion and with the severity of the threat for the U.S. government to suspend aid.

The loss of U.S. aid would deal a significant blow to the Egyptian military's finances. While Egypt's military budget is shrouded in secrecy, America's annual contribution is believed to comprise between a fifth and a third of the total, much of which is used to purchase American-made arms. That is only part of an intimate relationship between the two militaries that includes Egyptian officers frequently traveling to the United States to receive training.

Much bigger than the tangible impact of the loss of the revenue or weaponry would be a serious blow to a relationship to both sides, but certainly the Egyptian military, said McInerney. They've had an unusually close relationship with the world's strongest military for decades, and that comes with immense power and prestige.