Illegal immigration and national security

"The crisis caused by mass immigration has a decisive effect on Hungary's security. The crisis has made it clear that unexpected, uncontrolled, mass and illegal migration is a new type of challenge that can even jeopardize the security and stability of the European continent, while posing a range of risks to national security, public safety and public health. Given global processes, the challenge must be met in the long run." Hungary's newly published National Security Strategy

My Syrian refugee friends, who are Christians, told me years ago that refugees are the biggest threat to European security. I wrote about this in 2015 and quote from the article I wrote.

Admiral Christopher Parry, one of the Royal Navy’s cleverest strategists, warned in a paper in 2006 that Britain and Europe faced being overrun by mass migration from the Third World within 30 years, because of population growth and environmental destruction. The Internet, cheap flights and free international phone calls would hinder assimilation. (Is there anything left to assimilate to, nowadays?)
He compared the plight of the West to that of the Roman Empire in the fifth century. The Blair Government liked to encourage senior public servants to indulge in blue sky thinking but Admiral Parry had taken it too far. He was silenced and accused of racism.