Republican presidential candidate Donald Trump. Credit:Evan Vucci Here's an official Washington description of the NTC: "By identifying high-risk passengers and cargo well before they would cross our land borders, sail into our ports or touch down on our tarmacs, the N.T.C. team is on duty to protect our people and economy 24/7." Inevitably, the NCT and other such agencies are in a needle-in-a-haystack business. Which is why, whether addressing action in the US or abroad, before or after the September 17 bombs in and near New York, presidential candidate Donald Trump's views and policies would likely enflame domestic and international resentment of the US; and those of Hillary Clinton probably will take so long, if ever to be effective, that a solution remains elusive. In a succession of domestic attacks in the US, the perpetrators have been products as much of their former ethnic or religious culture as of the American cultural environment – which has its own violent strain. Consider:

Ahmad Khan Rahami is taken into custody after a shootout with police in New Jersey. Credit:AP Boston Marathon bombing – 4 dead, 280 injured in April 2013: The bomber Tamerlan Tsarnaev, 27, was only 16 and his accomplice and brother Dzhokhar, 20, was only 9 when their family migrated from the former Soviet Union in 2002

San Bernardino massacre – 14 killed, 22 injured in December 2015: Gunman Syed Rizwan Farook, 28, was born in Chicago in 1987; his Pakistani wife and accomplice Tashfeen Malik, 29, came to the US in 2014

Orlando massacre – 49 killed, 53 wounded in June 2016: Gunman Omar Mateen's parents migrated to the US from Afghanistan in the early 1980s – he was born in New York in 1986

New York/New Jersey bombings – 31 injured in September 2016: Alleged bomber Ahmad Khan Rahami came to the US with his family, from Afghanistan, as a 7-year old. He became a naturalised citizen in 2011

St Cloud, Minnesota, knife attack – 9 injured in September 2016: Assailant Dahir Adnan, 20, was 2 years old when his Somali family migrated to the US from Kenya. There are three elements to the election debate on countering terror in the US: the threat from those already living in the US; the threat from those who might come as refugees or migrants; and countering movements like Islamic State and al-Qaeda in their various theatres of war – physical, as in the failed and failing states in which they operate; and virtual – as in their thriving social media activities. In the case of Boston, Orlando and New York/New Jersey, there were complaints to US authorities, and checks made on the jihadist predisposition of the perpetrators – and ultimately all were cleared. So it's not clear that Trump's demand for ethnic and or religious profiling would be any more effective. Rahami's father gave his name to the FBI five months after his return from Pakistan, saying he was worried that his naturalised US citizen son was somehow connected to terrorism.

The context of the father's alarm was a violent family dispute in New Jersey. But despite so much official alarm just months earlier, the FBI still concluded it had no grounds to act against him – this time, Rahami didn't even warrant an interview. The massive investigation in the wake of the September 17 bombings in and near New York has revealed inspiration by ISS and al-Qaeda, but it is yet to turn up direct links between Rahami and such terrorist group. The only option for authorities, had they concluded that Rahami was a risk in 2014, would have been some kind of internment on an unproved suspicion – and this is the context in which Trump has not ruled out a contemporary version of Washington's internment of Japanese living in the US during World War II. In a December 2015 interview with Time magazine, Trump confessed that he might have supported such drastic action in the 1940s. He conceded resurrecting the policy was undesirable, but added that in confronting terrorism "war is tough". Trump has also called for terror suspects to be tortured; for the families of terrorists be "taken out"; for Muslim communities to be "patrolled"; and for a ban on Muslims entering the US – the last of which he reframed, when its first iteration met with a backlash even within his own party, as a ban on issuing visas in global regions affected by terrorism.

Trump is using the New York/New Jersey bombing to step up his calls for a crackdown on migration. Seemingly unaware that the perpetrators Farook and Mateen were US-born citizens, he told a rally on Tuesday: "Attack after attack — from 9/11 to San Bernardino to Orlando — we have seen how failure to screen who is entering the United States puts all of our citizens in great danger. "These attacks were made possible because of our extremely open immigration system, which fails to properly vet and screen the individuals or families coming into our country." Clinton, by contrast, demands greater vetting of would-be migrants, not a blanket ban. And domestically, she promotes the expansion of an existing pilot scheme in which people in just four communities across the country - Montgomery County in Maryland, Minneapolis-St. Paul, Los Angeles and Boston – are encouraged to report those who they worry have become radicalised or are troubled. Clinton sees the scheme relying on more than religious leaders. She wants to have teachers, sports coaches and doctors, along with family and friends who observe even subtle changes in behaviour to alert authorities to early signs of radicalisation.

A Clinton presidency would result in a benign outcome for US equities. Credit:AP Clinton also proposed enlisting Silicone Valley in an ambitious campaign to have the likes of Facebook, YouTube, Snapchat and the marketers of encrypted apps preferred by terrorists to remove radical speech from social media. Alive to inevitable First Amendment objections, she dismissed them recently – "You are going to hear all the familiar complaints: 'Freedom of speech'." A difficulty for Clinton is that what she offers is an extension of current policy. The Trump prescription, on the other hand is radical – and it risks kindling even greater jihadist and allied anger – particularly his proposal to seize control of oil resources to thwart IS' revenue raising. It's an idea that he has promoted as early as five years ago – and which has met only ridicule from analysts, policy makers and security experts. At a New York forum on September 7, Trump also argued that commandeering Iraq's oil would have helped to pay for the Iraq war – "We go in, we spend $US3 trillion, we lose thousands and thousands of lives, and then … what happens is we get nothing. You know, it used to be to the victor belong the spoils …One of the benefits we would have had if we took the oil ISIS would not have been able to take oil and use [it] to fuel themselves."

Impervious to arguments that his "spoils of war" justification is illegal, Trump has argued in various interviews: "You heard me, I would take the oil…"

"I would not leave Iraq and let Iran take the oil…"

"You're not stealing anything – we're reimbursing ourselves … at a minimum, and I say more. We're taking back $1.5 trillion to reimburse ourselves." "In international law, you can't take civilian goods or seize them. That would amount to a war crime," Anthony Cordesman, of the Centre for Strategic and International Studies told The New York Times. "Oil exports were almost the only Iraqi source of money. So you would have to pay for government salaries, maintain the army, and you have triggered a level of national animosity far worse than we did. It would be the worst kind of neo-colonialism. Not even Britain did that." Jay Hakes, the author of A Declaration of Energy Independence, wrote in Real Clear Energy: "It is hard to overstate the stupidity of this idea … Seizing Iraq's oil would make our current allies against ISIS our new enemies. We would likely, at the least, have to return to the massive military expenditures and deployment of American troops at the war's peak." The Baghdad government and the Kurdish autonomous region, not IS, control most of Iraq's oil and Syrian oil production is miniscule – and much of what IS controlled has been bombed by the US-led coalition that includes Australia.

To the extent that Trump has outlined the scope of his plan, he seems oblivious to the likely cost – military and diplomatic. Military experts estimate it might take as many as 100 000 troops to protect the oil wells and probably the occupation of much, if not all of Syria, already war-torn, to protect export pipelines that almost certainly would be targeted by terrorists. Loading And if the US did take Iraq's oil the rest of the region's oil producers, particularly those that are US allies, might reasonably consider themselves likely next targets, in the belief that a President Trump might want to recoup Washington's huge security investments across the Middle East – before or after he goes after NATO allies for the cost of their American protection. The whole scheme, and the fact that Trump clings to it in the face of expert rejection, makes it hard to disagree with the conclusion of former defence secretary and CIA chief Robert Gates, writing in The Wall Street Journal: "he is stubbornly uninformed about the world and how to lead our country and government, and temperamentally unsuited to lead our men and women in uniform. He is unqualified and unfit to be commander-in-chief."