When the national security legislation is introduced in Hong Kong, external meddling will end and local police can combat major crimes previously beyond their reach, says Laura Ruggeri, an Italian-born writer, researcher and academic.

Based in Hong Kong for 23 years, the former professor at the Hong Kong Polytechnic University said considerable damage had been done to the city due to it not having such a law.

She referred to months of often-violent protests Hong Kong has suffered since last June, triggered by a now-withdrawn extradition bill. The US and UK national flags were seen during these protests. Some Hong Kong activists went to the United States and met with US officials to lobby for economic sanctions on Hong Kong, in the hope that the SAR government would be coerced to compromise.

The Standing Committee of the National People's Congress, China's top legislature, on June 20 released details of the national security legislation proposed for the Hong Kong Special Administrative Region. The draft law, which includes 66 articles in six chapters, criminalizes secession, subversion of State power, terrorist activities and collusion with external forces.

Ruggeri said: "I don't understand the uproar, given that most countries have a national security law. It's designed to protect the country and its citizens from foreign forces and collusion." She said foreign meddling was just as much of a threat as terrorist-like violence.

The academic also criticized the city's opposition camp for their "unpatriotic" conduct in calling for sanctions to be applied to Hong Kong.

"I think it's most unpatriotic for the Hong Kong opposition camp to call for US sanctions. I don't see the opposition of any other country that would go as far as damaging the business prospects of their fellow citizens or the economy of their own country. It's perverse," she told China Daily during an interview.

Ruggeri also said the draft national security law doesn't go as far as the US Patriot Act — which was hastily passed after the 9/11 attacks.

"The Patriot Act allows the US government to spy on its citizens both at home and abroad." Ruggeri said. She cited an agreement in the Patriot Act between the US government and US-owned companies — including software and social media companies. They are obliged to share information on matters of national security. Ruggeri believes the national security legislation is more about preventing a "color revolution" in Hong Kong. It's not going to affect ordinary residents, she stressed.

The Italian-born author said the national security law would certainly safeguard the "one country, two systems'' principle. "You cannot have two systems without one country," she added.