He continued, "It is vital that the civilized world unite in the effort to hunt down all of the perpetrators who are still living. But for now, the killers remain at large. They are as much a threat to Europe, to America, and to the civilized world as they are to London."
As a result, the United States must redouble its efforts to prepare for terrorist attacks, said Cox. "While we cannot turn our transit systems into hardened targets, the aggressive measures underway are aimed at meeting both our security needs and the demands of a free society," he added.
He suggested the United States should step up deployments of remote surveillance technologies in mass transit systems, which will help prevent attacks as well as aid in the capture of those responsible.
Rep. Bennie G. Thompson (D-Miss.) said the attack in London "should serve as a reminder that America and our closest allies face perpetrators of evil threats who will stop at nothing to inflict harm and pain. As our nations continue to remain vulnerable to terrorist attacks, we must remain vigilant – and we must plug up the holes and inconsistencies in our current efforts to protect the American homeland. Almost 4 years after the Sept. 11, 2001 terrorist attacks, passenger rail and public transit security remains an afterthought."
Thompson added, "our thoughts, prayers and well wishes are with the city of London and the victims of [the] terrorist attack. We know the people of London are resilient and England has been resolute in fighting the war on terror."
The president of the union representing workers in the Department of Homeland Security offered the condolences of the American Federation of Government Employees (AFGE) to the families who lost loved ones in the London subway attacks.
"As civil servants sworn to protect the American people and their homeland, we express our solidarity with the people of the United Kingdom – most especially with the public servants who attended to the innocent commuters who endured this gruesome assault, and those who prevented such attacks in the recent past."
He offered reassurances to the American people, saying, "In this time of danger and sadness, we rally with all in the Homeland Security Department, labor and management alike, ever resolute in our duty to protect the American people."