COLOGNE could be more vulnerable than ever for terror attacks as short staff police are distracted by petty criminals and focusing on preventing a repeat of last year’s sex assault drama. Terrorism experts have warned ISIS are looking to strike western targets over the festive period with the final day of the year providing an opportunity for them to take many lives. Political scientist and terror expert Dr Colin Clarke from think tank RAND has warned many in his line of work fear the worst this year.A threat from ISIS - combined with staffing issues - could lead to a Paris or Nice-scale attack. He said: “New Years Eve in general is an opportune time for jihadists to strike, particularly since police will likely be occupied with other types of things, including general drunkenness and assaults that usually go hand in hand with over-imbibing. “NYE is one of the nights when resources are stretched thin, not only for police but for other first responders like EMS and fire & rescue workers. “It also provides opportunities to target large outdoor gatherings and the fireworks can provide ideal cover for other explosions or gunfire. I'm very concerned that something could be attempted in a European city. “The main problem is, especially in Europe, there are too many targets for law enforcement to monitor and surveil, especially in countries like France, Belgium and now it seems, Germany. “I only expect things to get worse.”Terror experts have claimed recently there is a connection between criminal gangs in Europe and Islamic State - leaving question marks over whether they could work together to distract police. Academics have debated the existence of what has been dubbed the “crime-terror nexus” - suggesting there exists an intersection between crime and terror. Groups of criminals are accused of working with ISIS and providing information to aid and assist attacks. Terrorists who have been in trouble with law enforcement before carrying out atrocities include Abdelhamid Abaaoud, leader of the fall 2015 Paris attacks, and Ahmed Coulibaly, a key figure in the Charlie Hebdo attacks in Paris earlier that same year. Mohamed Lahouaiej Bouhlel, the terrorist who killed 84 people in July by driving a truck through a crowd on Bastille Day in Nice, France, also had a history of petty crime.Thomas Hegghammer in the Terrorism Research Initiative, predicts there are around 2,000 jihadis in Europe with fighting experience - or who have served time in prison. The senior research fellow at the Norwegian Defense Research Establishment (FFI) in Oslo wrote if European police forces fail to tackle the issue, Europe could see a wave of attacks “in the next two to five years”. Between 2014 and 2016 273 people were killed in “jihadi” attacks in Europe- more than every other year before it combined. Dr Clarke said it is difficult to predict where an attack may be since ISIS is likely to have spread across the entire EU. He said: “IS may have deployed hundreds of operatives into the European Union already, according to some reports, ensuring an effective “international terrorist strike capability” for the better part of the next decade. “The post-IS diaspora is likely to have more connections to the European underworld than ever.”In Cologne, police are preparing extra cells for attackers, drunks and criminals after chaos broke out at the central celebrations last year, and more than 100 women reported being robbed or sexually assaulted. After Berlin, the police are not only worried about policing attackers, but terror incidents in the city. Police president Jürgen Mathies revealed plans are in place to try to prevent a mass attack. He said: "We have decided to concentrate all available forces in the area of the inner-city. “Some of them will be wearing especially bulletproof vests and machine guns. In addition there will be intense traffic controls, more than 50 police officers are checking vehicles at six different locations since Tuesday. They were especially focussed on trucks and mini vans. “The third measure are mobile truck barriers in the form of mini vans that will be placed at entrances of Christmas markets from 11am to 11pm.” Law enforcers could find themselves distracted on New Years in Cologne as protestors announce they will gather in the centre of the city. The National democratic Party of Germany (NPD) will march ‘against the right’ on the night.