Integrated Review

The Integrated Review of Security, Defence, Development and Foreign Policy, often known as the Integrated Review, and titled as Global Britain in a Competitive Age, is a review by the British Government into the foreign, defence, security and international development policies of the United Kingdom. Described by Prime Minister Boris Johnson as "the largest review of its kind since the Cold War", the review was published on 16 March 2021. 
The review sets out the government's vision for Global Britain, the UK's role in the world following its withdrawal from the European Union. Its four overarching objectives are for the UK to sustain a strategic advantage through science and technology, for the UK to shape the open international order through working with partners and international institutions, for the UK to strengthen its security at home and abroad and for the UK to become more resilient to threats at home and overseas. The review identified Russia as an "active threat", China a "systemic challenge" and climate change the UK's highest international priority. It was first announced in December 2019 by the first Johnson ministry with a publication date set for "early 2020", however the COVID-19 pandemic caused it to be delayed several times. A number of preliminary decisions were published in November 2020 ahead of the review's full publication. 
A defence command paper, titled "Defence in a Competitive Age", was published by the Ministry of Defence on 22 March 2021 which outlined changes to the armed forces in order to meet the objectives of the Integrated Review.
Background.
The Integrated Review combines previously separate reviews into foreign policy, defence, national security and international development, such as the National Security Strategy and the Strategic Defence and Security Review into one, making it the largest review of its kind carried out by a UK government since the Cold War. It follows several notable developments since previous reviews, namely the United Kingdom's withdrawal from the European Union, the start of the COVID-19 pandemic and consequent economic downturn, the 2019–2020 Persian Gulf crisis, the rise in space warfare, several terrorist attacks and the use of hybrid warfare, particularly by Russia and China. The review also follows the merging of the Foreign and Commonwealth Office and Department for International Development into the Foreign, Commonwealth and Development Office which occurred in September 2020.
Overview.
The review was first announced during the December 2019 State Opening of Parliament in a speech outlining the second Johnson ministry's plans for that parliamentary year.
Objectives.
In a statement in September 2020, Prime Minister Boris Johnson confirmed the Integrated Review would be underpinned by a commitment to spend at least 2% of GDP on defence—as defined as a target by NATO, 0.7% of GNI on Official development assistance and the maintenance of the British nuclear deterrent. The Prime Minister summarised the review's objectives as follows:
In September 2020, Defence Secretary Ben Wallace explained that the review would deliver an armed forces that was "fit for tomorrow's battles" by switching from "traditional warfighting" to "technological warfighting". He explained that this would entail being forward deployed — for example, in Europe to deter Russian activity, in the Middle East to combat terrorism or in the Asia-Pacific to counter China — and relying on technology to deliver "speed, readiness and resilience" instead of "mass and mobilisation", including in the domains of space, cyberspace and sub-sea.
Complications.
The review suffered several delays due to the COVID-19 pandemic, causing it to miss its original publication date of "early 2020". The review was first postponed in April 2020 but was restarted in July of that same year, with an unspecified publication date. A call for evidence was published on 13 August 2020 by the Cabinet Office. In October 2020, the review's future came into question once again following a decision by the government to implement a separate spending review, which covered one year instead of three, due to the economic uncertainty caused by the COVID-19 pandemic. A new publication date for February 2021 was then set but was subsequently missed, due again to the pandemic. This date was then replaced by one during March.
Decisions.
In November 2020, Johnson announced an investment of £16.5 billion into defence over four years — representing a share of over 2.2% of GDP — as the first conclusion of the Integrated Review. Reported as the "largest military investment in 30 years", Johnson stated: "This is our chance to end the era of retreat, transform our Armed Forces, bolster our global influence, unite and level up our country, pioneer new technology and defend our people and way of life". The investment amounts to an increase of between 10–⁠15 percent on the current annual budget of £41.5 billion. 
The full review, titled "Global Britain in a Competitive Age", was published on 16 March 2020 by the Ministry of Defence. It resulted in the following notable conclusions:
Defence in a Competitive Age.
Following the publication of the Integrated Review, the government published a Defence Command Paper, titled "Defence in a Competitive Age" on 22 March 2021. The document outlined the government's planned investments and savings to defence to allow it to meet the objectives set out in the Integrated Review.