In March of this year, the US, France, Britain and their North Atlantic Treaty Organisation (Nato) allies launched military operations in Libya under the guise of a "humanitarian intervention". US diplomats and world leaders carelessly voiced unsubstantiated claims of an impending massacre in Benghazi. You hear no such appeals to humanity while Nato, in the name of the rebels (whoever they are), prepares to lay siege to Tripoli, a city of nearly 2 million people.

Libyan rebels are now advancing on the capital city of Tripoli with the aid of Nato strikes; this is sure to result in a real bloodbath, as opposed to the one that was conjured in Benghazi this past winter. Nato is assisting rebels who are blocking food, water and medical supplies from coming into the capital city, and is stopping those who need advanced medical care from travelling to Tunisia to access it. Nato is bombing power stations, creating blackouts, and using Apache helicopters to attack Libyan police checkpoints to clear roads for rebels to advance.

Regardless of whether Muammar Gaddafi is ousted in coming days, the war against Libya has seen countless violations of United Nations security council resolutions (UNSCRs) by Nato and UN member states. The funnelling of weapons (now being air-dropped) to Libyan rebels was, from the beginning of the conflict, in clear violation of UNSCR 1970. The use of military force on behalf of the rebels, in an attempt to impose regime change, has undermined international law and damaged the credibility of the United Nations. Countless innocent civilians have been killed, and Nato air strikes continue to place many at great risk.

So much for the humanitarian-inspired UNSCR 1973 as a means to protect civilians. The people of Libya cannot take another month of such humanitarian intervention.

The leading donor nations of Nato – the US, France and Great Britain – have been free to prosecute war under the cloak of this faceless, bureaucratic, alphabet security agency, now multinational war machine, which can violate UN resolutions and kill innocent civilians with impunity. War crimes trials are only for losers. The prospective conquerors, the western powers and their rebel proxies, will then expect to be able to assert control over Libya's vast oil and natural gas reserves.

The US share of the war against Libya has probably exceeded the $1bn mark. This extraordinary amount of money for an intervention that Americans were told would last "days not weeks" could only be explained by looking at the war as an investment, and at control over Libya's wealth as an opportunity to make a return on that investment. Cynical? Then tell me why else we are at war in Libya.

Viable peace proposals, such as the one put forward by the African Union (AU), have been quickly and summarily rejected. If there is going to be a peaceful resolution of the conflict, the US must work with and empower the AU to ensure regional security. The AU has proposed a peace plan that would facilitate an immediate ceasefire, the unhindered delivery of humanitarian aid, a dialogue between the Transitional National Council and the Gaddafi government, and the suspension of Nato strikes.

The use of force and ultimatums has not worked. As the war enters its sixth month, it is time for the US president and secretary of state to clean up the mess they've created with this needless military intervention, and to work to seriously to bring about a negotiated end to this war.

In June, I proposed a peace plan (pdf) derived in part from the efforts of the AU. This plan calls for an immediate ceasefire and lays out the principles necessary to create a framework to achieve reconciliation and national unity in Libya by a meaningful process. In its June report on Libya, the International Crisis Group stated:

"A political breakthrough is by far the best way out of the costly situation created by the military impasse. This will require a ceasefire between the regime and the Transitional National Council, the deployment of a peacekeeping force to monitor and guarantee this under a UN mandate, and the immediate opening of serious negotiations between regime and opposition representatives to secure agreement on a peaceful transition to a new, more legitimate political order. Nato and those states supporting its military action should facilitate this development, not hinder it."

I have recently received several reports indicating that a settlement was close, only to be scuttled by state department officials. Given that the department of state seems to have taken a singular role in launching the US into this war, it is more than disconcerting to hear that the same agency has played a role in frustrating a resolution to this conflict. There are viable solutions to peacefully end the conflict, if there is a desire to do so.

Continued military action promotes a cycle of violence that will persist whether Colonel Gaddafi is ousted or not. On 19 March 2003, the United States pursued regime change in Iraq. Eight years later, we're still wondering why the people of Iraq are not sufficiently grateful for our intervention, which has resulted in the death of over 1 million of their fellow countrymen and women.

How can we expect this grim manifesto of interventionism to ever result in anything but tragedy? It's time to end the war against Libya.