Secretary of State for Defence
On 24 July 2019, Boris Johnson became prime minister and immediately appointed Wallace as Secretary of State for Defence, replacing Penny Mordaunt, who was left out of the new government. In August 2019, Wallace was overheard discussing Johnson's controversial prorogation of parliament with Florence Parly, the French Armed Forces minister. He suggested that the reason for the prorogation for five weeks was to prevent MPs from blocking the government's Brexit plans, rather than the government's official position that it was to introduce a new legislative agenda. 10 Downing Street responded to his comments by admonishing him and stating that he had "misspoken". This prorogation was deemed unlawful by the Supreme Court on 24 September 2019.
On 13 October 2019, in a NATO meeting, Wallace defended the 2019 Turkish offensive into north-eastern Syria. He commented, "Turkey needs to do what it sometimes has to do to defend itself". His comments were condemned by other delegates at the meeting. On 12 January 2020, in an interview with The Sunday Times, Wallace said that the UK "must be prepared to fight wars without the US", one of the UK's key allies. He stated that the upcoming defence review "should be used to make the UK less dependent on the US in future conflicts". His comments were made in response to US President Donald Trump's "America First" isolationist policies. Wallace also said that the next defence review would be the "deepest review" of Britain's defence and foreign policies since the end of the Cold War in 1991. On 15 March 2021, as part of the Integrated Review, Wallace released a command paper titled Defence in a Competitive Age, in which he detailed "a mission to seek out and to understand future threats, and to invest in the capabilities to defeat them," promising an expenditure of £188 billion on defence over the next four years.
In July 2021, Wallace said that the United States had left Britain in a "very difficult position" following the withdrawal of most US troops from Afghanistan. Soon after the withdrawal of US troops had started, the Taliban had launched an offensive against the Afghan government, quickly advancing in front of a collapsing Afghan Armed Forces. Wallace said the UK would be ready to work with the Taliban should they come to power provided they adhere to certain international norms. On 16 August 2021, during a radio interview on LBC about the withdrawal from Afghanistan, Wallace was asked by an LBC interviewer, "why do you feel it so personally, Mr Wallace?" He replied with emotion: "because I'm a soldier ... because it's sad, and the West has done what it's done and we have to do our very best to get people out and stand by our obligations".
Wallace was the minister responsible for the British evacuation from Kabul, Operation Pitting. He was involved in a controversial decision to allow Pen Farthing – who ran an animal sanctuary in Kabul – to evacuate 71 people and more than 100 animals from Kabul to the UK. Wallace said Ministry of Defence staff had suffered abuse from some of Farthing's supporters, who alleged the government had initially abandoned Farthing. In December 2021, Wallace met with Saudi Arabia's Crown Prince Mohammed bin Salman to discuss cooperation in various fields, especially defence, having discussed similar matters the previous year with Saudi Arabia's vice defence minister Prince Khalid bin Salman. In 2022, at an event to mark the 40th anniversary of the end of the Falklands War, Wallace declared Britain's determination to "stand up to bullies". His words were decried as "belligerent threats" and "denigrating references" by Argentina.
Wallace met Sergei Shoigu, the Russian Minister of Defence in Moscow on 11 February 2022. Shoigu reiterated a denial of any Russian intentions to invade Ukraine. The following day, Wallace said that a Russian invasion of Ukraine was "highly likely", and British citizens were being told by the Foreign Office to evacuate while commercial means were still available. Ukraine's ambassador to the UK, Vadym Prystaiko, said Wallace's comparison of diplomatic efforts with Russia to the appeasement policies of the 1930s was unhelpful, saying now is the wrong time to "offend our partners". On 23 February 2022, Wallace was filmed saying that the Scots Guards "kicked the backside" of Nicholas I of Russia during the Crimean War, and could do so again. Russia invaded Ukraine the following day.
On 21 March 2022, clipped footage of Wallace in a prank call by Russian pranksters Vovan and Lexus was released online. The duo (suspected by the British government to have links to Russian security services or of being Russian state actors) impersonated the Ukrainian prime minister Denys Shmyhal saying that Ukraine wished to promote its own nuclear deterrent to protect itself from Russia, a false claim made by the Russian government during the Russo-Ukrainian War and the invasion of Ukraine. Wallace was believed to be on a Microsoft Teams call with the duo for ten minutes. That day, Wallace announced plans to reduce the number of British Army personnel from 76,500 to 72,500.
Wallace was perceived as responsible for initial British reluctance to send Challenger 2 tanks to Ukraine in March 2022, saying that the idea "wouldn't work". Boris Johnson and his German counterpart Olaf Scholz agreed on 8 April that both European allies would withhold their Western-designed main battle tanks from the fray. Johnson instead chose to backfill the Polish Army, thus allowing them to send their obsolete T-72s to Ukraine, while they waited for their order of South Korean K2 Black Panther replacements. Despite a planned reduction of the British tank fleet from 227 Challenger 2 tanks to 148 upgraded Challenger 3 tanks, there were no plans to send British tanks to the Ukrainians. Wallace later announced that the number of Challenger 3 tanks required by the UK was under review. In January 2023, the British position was reversed, and Challenger 2 tanks were supplied to Ukraine in March 2023.
Boris Johnson announced his intention to resign as prime minister and leader of the Conservative Party in July 2022 following a series of mass resignations from his government. Wallace was seen as a contender to succeed him as party leader and thus prime minister, but on 10 July he ruled himself out from entering the contest. In a statement on Twitter, he said his focus was on his current job and "keeping this great country safe". He later endorsed Liz Truss in the election. Following the appointment of Truss as prime minister, Wallace was reappointed to his post on 6 September 2022. He retained his post when Rishi Sunak became prime minister on 25 October. On 7 November 2022, Wallace announced that the competition to build a new national flagship yacht would be scrapped with immediate effect.
On 19 January 2023, Wallace together with the defence ministers of Estonia, Poland, Latvia and Lithuania; and the representatives of Denmark, the Czech Republic, the Netherlands, and Slovakia issued the Tallinn Pledge, "to reaffirm our continued determination and resolve to supporting Ukraine in their heroic resistance against the illegal and unprovoked Russian aggression."
On 21 June 2023, Wallace ruled himself out of the running to become the next NATO Secretary-General after rumours spread that the US were in favour of Jens Stoltenberg staying in post.
Speaking at a NATO summit in Lithuania on 11 July, Wallace said that Ukraine should offer more gratitude to Western allies of the country, following the Ukrainian president Volodymyr Zelenskyy's frustration at not being given a formal invitation to join the NATO alliance. Wallace also said that American and British lawmakers felt that Ukraine was demanding an Amazon-style wishlist of demands in military aid.
On 15 July 2023, Wallace announced his intention to resign as Secretary of State for Defence at the next Cabinet reshuffle and confirmed that he would not be seeking re-election as an MP at the 2024 general election. By length of tenure, he was the longest-serving Conservative Secretary of State for Defence on record. Wallace was also the longest-serving participant in the current UK Cabinet by continuous service; attending without interruption since his 2016 appointment as Minister of State for Security. On 31 August 2023, Wallace formally resigned as Secretary of State for Defence.
