Despite Trump's national defense budget reaching near historical records, defense expenditure got the largest hike under Bush during the Iraq War.
While Bush's defense spending increased 36 percent in his first four years owing to the Iraq War, Trump's increased by 18 percent, according to a Cato Institute report. Meanwhile, a Forbes report states that the current administration increased defense outlays by 25% in their first term — a bump in funding more significant in size than the entire military budget of any country other than China.
Trump's defense budget has repeatedly come under scrutiny, particularly after he called the U.S. defense spending levels 'crazy' in December 2018, only to announce plans for a $750 billion defense budget just a week later. In 2019, the Department of Defense's discretionary budget had been approved for $686.1 billion, and in 2020 it rose to $738 billion.
The White House was also criticized for increasing defense budgets while steep cuts were introduced to domestics programs involving healthcare and education. According to Slate, Trump proposed a $740.5 billion national security budget for 2021, which, despite being marginally higher than the current years' budget, is the largest since World War II.
Therefore, even though the current administration significantly increased defense budgets, Bush's numbers were higher during the Iraq War. Because of the circumstances in which both presidents took over, Pence's statement does not hold up until the current budget.