The deadliest terrorist attack in New York

The deadliest terrorist attack in New York since 9/11 has once again put the spotlight on US measures in place to prevent such attacks.
The suspected attacker, Sayfullo Saipov, is a citizen of Uzbekistan who entered the US legally in 2010.
On Tuesday afternoon, Saipov drove a rented truck into a busy bike path in lower Manhattan along the Hudson River, killing eight people and injuring at least 11 others. Five of the victims were tourists from Argentina.
US media outlets are reporting that Saipov was under the radar of counterterrorism officials, and might have been previously questioned by the Federal Bureau of Investigation (FBI). 
It is not clear whether he had raised concerns because of his behavior and activities, or because of his affiliation with possible suspects in other investigations.
Eyewitnesses told police that the attacker allegedly began screaming “Allahu Akbar” (God is Greatest) upon getting out of the truck, which struck a school bus before stopping. Officials investigating the attack are suggesting that literature was found near the crime scene suggesting that Saipov might have pledged allegiance to Daesh.
So far authorities are treating the crime as having been inspired by the terrorist group, but are yet to establish a connection between Saipov and Daesh that suggests it provided him with operational support.
Almost immediately after news of the attack was reported, President Donald Trump began commenting about it on his Twitter account.
On Wednesday morning, he appeared to assign at least partial blame for the attack on immigration laws passed by Democratic lawmakers.
“The terrorist came into our country through what is called the ‘Diversity Visa Lottery Program,’ a Chuck Schumer beauty. I want merit based,” Trump tweeted, referring to the Democratic senator.
Frances Townsend, homeland security and counterterrorism adviser to former President George W. Bush, and president of the Counter Extremism Project, said the attack suggests that Daesh continues to inspire attacks in the US and beyond.
“This attack followed the ISIS (Daesh) playbook: Use a truck or car, leave a note attributing it to ISIS, then get out with a knife or gun,” Townsend told Arab News.
He said the timing and location were not coincidental, and were meant to inflict significant damage and have symbolic value, being a few blocks away from the location of the World Trade Center.
The attack is likely to raise questions about whether Uzbekistan is facing a threat to its national security by militant groups. 
John G. Horgan, professor of global studies and psychology at Georgia State University, said challenging political conditions have led to a surge in Uzbeks leaving in search of a better life, and some have joined conflicts in other countries.
“Many Uzbeks joined Daesh, and this isn’t the first time an Uzbek national has been involved in terror attacks in the West,” Horgan told Arab News.
“An Uzbek man was involved in ramming a truck into a crowd of people in Sweden earlier this year.”
Townsend expressed similar concerns, saying: “Uzbekistan has long had an extremism problem.”
As to whether the attack will lead to tougher immigrations policies in the US, Mathew Levitt, director of the Stein Counterterrorism Program at the Washington Institute for Near East Policy, expressed doubts about the effectiveness of such measures.
“Implementing a restrictive immigration policy isn’t going to address this problem,” he told Arab News.
“The most immediate threat today comes from individuals who’ve been radicalized at home. The radicalization didn’t happen abroad, it happened here