The Government has announced a security shake-up as it has warned the Islamist terrorism threat may increase during the next two years.
Theresa May warned that Britain's enemies should be in no doubt that "every capability at our disposal" will be used to defeat them.
She added that the nerve agent attack in Salisbury has underlined the need for the UK to make better use of its financial, cultural and diplomatic clout as well as military force to quash threats.
Unprecedented levels of intelligence have been shared with international allies following the poisoning of former spy Sergei Skripal and his daughter Yulia.
The new "fusion doctrine" which is to call on all Whitehall departments and agencies to play a part in boosting security, there will also be changes to the way decisions are taken at the top of Government to prevent any repeat of the UK's failings in the Iraq war.
The Government said it will use a more accountable system to support collective Cabinet decision-making in the wake of the Chilcot report.
The National Security Capability Review (NSCR) states the threat from Islamist terrorism is expected to remain at its current heightened level for at least the next two years and might increase further.
In the foreword to the report, May wrote "over the past year in the UK we have witnessed appalling terrorist attacks in London and Manchester" as well as the nerve agent attack in Salisbury.
"As long as we defend our interests and stand up for our values, there will continue to be those who seek to undermine or attack us.
"But these people should be in no doubt that we will use every capability at our disposal to defeat them."
Around £56 billion is spent annually on national security capabilities, which will rise to £60 billion in the coming years.