After the murders in Paris, the fear others remain at large in France; the raids in Berlin and yesterday's raids, with two dead Jihadists in Belguim - the UK police have started a review regarding the safety of the Jewish community and police officers:
....in light of the attacks in Paris last week, we have been reviewing, alongside our partners, our overall security posture. This is a further step in a process over a number of years of learning lessons from such events. For example, since the attack in Mumbai in 2008, we have enhanced our ability to respond effectively to a marauding terrorist attack by expanding our specialist firearms capability and improving the effectiveness of the response and joint working of all the emergency services. More generally we have continued to refine our plans and to enhance our capabilities to respond to a terrorist threat which has evolved and diversified.

(Later) We are also considering what further measures we might put in place to enhance the security of police officers, given some of the deliberate targeting of the police we have seen in a number of countries across Europe and the world. Chief Constables across the country are reviewing how to strengthen the protection of their officers from such attacks. Our men and women on the frontline are used to confronting risk and danger and are well-trained in how to protect the public and themselves.
Link:http://news.acpo.police.uk/releases/...MKd72V.twitter

So no more - via a media Tweet - single officer patrolling.