I personally believe that Theresa May is doing what she can in the circumstances to protect us and our country. I would be interested to know specifically what more could be done to prevent this happening? As for the security threat level being raised to critical, if you follow these things you will be aware that the level has been SEVERE for a long time now, and raising it to CRITICAL after the attack simply means that the security forces have made the Government aware that they have evidence of a risk that further attacks could yet be carried out as a RESULT of the first attack. It suggests also that this time, the man was not working alone, and others unfortunately were aware this was going to happen and are intent on causing further carnage. Westminster may have been a lone wolf attack, but this has all the signs of it being a planned and co-ordinated attack.