The UK must "wake up" to the threat posed by China's challenges to global security, the ex-head of MI6 has said.
Sir Alex Younger, who led the UK's Intelligence Service between 2014 and 2020, said Western nations are "under full press of Chinese espionage".
US military have shot down four objects - including a suspected Chinese spy balloon - in the past week.
Sir Alex said the UK must place limits on tolerating countries "who behave in an unacceptable way".
On 4 February, the US military shot down a Chinese spy balloon after it travelled over sensitive military sites across North America. China has claimed the object was a weather balloon gone astray.
Since then, the three other "unidentified objects" have been downed across North America.
Speaking on BBC Radio 4's Today programme, Sir Alex said "this balloon scenario demonstrates there is no trust" between China and western nations.
"This is a gross and really visibly transgression of the sovereignty of many nations."
The UK must recognise "we're in a competition" with China, Sir Alex said.
He said: "We need to wake up to this.
"We need to double down on the strengths that we possess to face this systemic competition that's going on."
The Ministry of Defence is conducting a security review following the incursions into North American airspace.
Defence Secretary Ben Wallace said: "The UK and her allies will review what these airspace intrusions mean for our security.
"This development is another sign of how the global threat picture is changing for the worse."
Prime Minister Rishi Sunak has said the government will do "whatever it takes" to keep the UK safe from spy balloons.
On Monday the prime minister said a "quick reaction alert force" of RAF Typhoon jets was on stand-by 24/7 to police UK airspace.
Security risks
In November, Mr Sunak declared the so-called "golden era" of UK relations with China over after seven years of closer economic ties promoted by David Cameron's administration.
The UK's mobile providers are banned from buying new 5G equipment from Huawei, over fears the technology can be accessed by the Chinese state.
Companies must also remove all the firm's 5G kit from their networks by 2027.
Huawei has denied being controlled by the Chinese government or posing a security threat.
A cross-party group of MPs, including former Tory leader Sir Iain Duncan Smith, are calling for Chinese governor Erkin Tuniyaz to be arrested during a potential visit to the UK this week.
Mr Tuniyaz is head of the Xinjiang province, where the UN has said crimes against humanity may be taking place against Uyghurs.
Sir Iain was sanctioned by the Chinese government in 2021 along with dozens of MPs over their criticism of human rights abuses in Xinjiang.
Source: BBC
Image: Getty Images
