Long Island Congressman Peter King insists that the mall attack signifies that America itself is vulnerable, that new level of vigilance is needed if another 9/11 is to be avoided. In particular, King is fixated on the idea that trained jihadists will return from the far battlefield and recruit and train others, possibly for targets in the US.

Should the situation, as King has warned, cause Americans to fear for a similar or related attack along the lines of the Nairobi mall attack? Does it compel a new course of action for counterterrorism experts and officials in the US? The answer is that the Nairobi attack may neither suggest either the possibility of a similar incident occurring in the US nor a doubling-down on counterterrorism activities in the US.

At the centre of the concerns of Congressman King and others is the relationship between Al Shabab, the terrorist organisation that was leading the Nairobi attack, and the Somali-American community. Kenya’s foreign minister has focused attention on this issue by reporting that several of the terrorists are “Americans”. So, here are some of the relevant facts. Somalia is engaged in a violent civil war in which the government is opposed by a number of radical insurgent groups, including the Al Qaida-linked Al Shabab. Al Shabab is dedicated to ousting the current regime and establishing a government based on harsh Sharia.

The United Nations and the US support the current government and thus the African Union Forces — largely from Kenya and Ethiopia — that are engaging Al Shabab and others on behalf of the government of Somalia. Significantly, the opposition to Kenyan and Ethiopian intervention in Somalia — carrying with it a longstanding historical bitterness — is shared by non-Islamic groups as well.

Since the beginning of the rise in hostilities in the civil war, many Somali Americans have agreed with the opposition to the current regime. Many of these Somali Americans have gone abroad for the purpose of ousting the current government and pushing back against African Union Forces. Many have joined Al Shabab in the process. Supporting a foreign terrorist organisation is against US law and indictments have been filed in federal court against the known foreign fighters from the US. Several of those against whom the indictments have been filed have been apprehended abroad and convicted in federal court. Others remain at large.

According to King, and others, the prospect of these foreign fighters returning to the US and recruiting and training others, poses a grave danger to the US. However, here are some additional relevant facts that shed some doubt on the assertion that fighters from Somalia necessarily pose a danger to the US.

First, none of the individuals who travelled to Somalia and who were eventually arrested and convicted, was accused of planning an attack on the US. Their crime was giving aid and support to a foreign terrorist organisation that has not attacked the US. Second, in the US proper, where Somali-Americans donating funds to Somalia-based causes are often under suspicion for providing material support for terrorism, there have been numerous convictions for financing Al Shabab. But not one of these individuals has been linked to plans for an attack on the US.

And finally, in the only case where a Somali American was accused of planning a violent attack in the US — Mohammad Mohammad, who was accused and convicted after participating in a Federal Bureau of Investigation sting operation to bomb a Christmas Day parade — there was no accusation of a link to Al Shabab or any other terrorist organisation. Even Omar Hammami, considered for a time the highest-ranking American in Al Shabab, who eventually broke with the organisation, was not accused of calling for violence against the US.

In sum, the terrorism prosecutions against Somali Americans allegedly involved with Al Shabab have been for recruitment and financing an extremist cause abroad, not for plotting to harm Americans on American soil. So, why does Congressman King persist in fear-mongering despite evidence to the contrary?

The answer lies in the worry that foreign fighters who end up joining jihadist causes abroad could prove lethal if they returned home to recruit; that nationalist causes all too often go hand-in-hand with the call for an Al Qaida-style global jihad. However, given the absence of such behaviour among Somali Americans, is not the converse also true? That Somali Americans can believe they are helping to support a nationalist group abroad and that even if they are misguided in their attempts to fund foreign extremists, that they are not intent upon harming the US?

After all, the Somali diaspora in the US has demonstrated — for example, in Minneapolis and St Paul, where many of the foreign fighters come from — a strong determination towards integration into the American way of life via educational institutions, business and civic organisations. And do we really want to assume the worst as a means of prevention? Have we become a society too scared to think that our law enforcement officials can weed out those who pose a danger to the US from those who break the law in a misguided effort to support local causes abroad?

Once again, it seems, when it comes to fears of domestic terrorism, suspects in the US are guilty until proven innocent.

— Guardian News & Media Ltd

Karen Greenberg is director of the centre on national security at Fordham University law school. Formerly, she was director of the centre on law and security at NYU law school and is the author of The Least Worst Place: Guantanamo’s First 100 Days.