The ceremony marking the 11th anniversary of the Sept 11 attacks at Ground Zero in New York on Tuesday morning was the first held without any speeches by government officials, in order to make it a moment of pure remembrance.

Yet politics arising from the terrorist attacks in 2001, which has dictated much of US foreign and domestic policy since, is not going to go away anytime soon.

In his weekly address on Saturday, US President Barack Obama said the US has come back stronger as a nation, decimated the leadership of al-Qaida and ensured that Osama bin Laden will never attack America again. He did not forget to congratulate himself on ending the war in Iraq and overseeing the transition in Afghanistan that will be completed by 2014.

Obama, regarded four years ago as weak on counterterrorism, has proved in poll after poll that national security is his strength. Compared to Republican challenger Mitt Romney, Obama has a clear lead in that area.

At last week's Democratic National Convention in Charlotte, North Carolina, many speakers lauded Obama for bin Laden's killing.

But in the last four years, Obama's track record on counterterrorism has surprised both his supporters and opponents.

To the disappointment of many Democratic supporters, Obama preserved rendition, which allows terror suspects to be transferred to countries where harsh interrogation techniques, or torture, are employed.

In his first year in office, Obama ordered a surge of 30,000 troops in Afghanistan. He has authorized an increasing number of drone attacks. He sanctioned 283 strikes in Pakistan, eight times more than the Bush administration did in eight years.

While Obama, former CIA director Michael Hayden and others defend drones as an accurate and effective tool to eliminate key enemies, human rights groups and many Obama followers have been critical of the targeted killings, which caused collateral civilian deaths. Some have referred to the drone strike that killed US-born cleric Anwar al-Awlaki in Yemen as the assassination of an American citizen.

Many have been angry with Obama for breaking his promise, made four years ago, to close the prison at Guantanamo Bay, where suspected terrorists are held indefinitely without trials.

On Monday, the US military announced that one prisoner had died in the high-security prison, bringing the number of prisoner deaths at the facility to nine since it opened in 2002. A total of 167 prisoners are still kept there.

Benjamin Wittes, a senior fellow and an expert on counterterrorism and national security at the Brookings Institution, said on Monday that both drone attacks and Guantanamo are boosting recruits for al-Qaida. "Drone attacks are the recruiting tool right now," he noted.

Stephen Grand, who heads the Project on US Relations with the Islamic World at Brookings, criticized the use of armed drones, saying it turned a blind eye to the very real human costs, namely civilian casualties from "targeting errors".

He criticized preemptive strikes and targeted killings of leaders as actions that failed to consider the wider forces fueling international terrorism, such as "extreme poverty, youth unemployment and limited opportunities for education".

He lamented the experience of US Muslims in the past decade.

A Pew Center report released a year ago showed that 52 percent of American Muslims say that government anti-terrorism policies single them out for increased surveillance and monitoring.

As people marked the 11th anniversary of the Sept 11 attacks, the Park51 - once known as Cordoba House, or the Islamic cultural center, under construction a few blocks from Ground Zero - remained a contentious issue.

A CNN poll two years ago showed that 70 percent of Americans opposed it.

Writing in the Huffington Post on Monday, New York University professor Marita Sturken and Vassar College Professor Katherine Hite said: "If the Sept 11 Memorial Museum could tell the history of 9/11 in a meaningful way, it too would have to address the question of human rights, not only to see terrorism as violence against human rights, but also to examine the abuses of human rights committed by the United States in response to that day's tragedy - the wars in Afghanistan and Iraq, the torture of prisoners at Guantanamo and Abu Ghraib, the drone wars."