Elaine McCusker, a top Pentagon official during the first Trump administration, told me she estimates that by the end of its sixth day, the war’s cost exceeded $11 billion, including more than $5 billion worth of interceptors. To replenish its arsenal, the Pentagon is expected to ask Congress for an additional $50 billion. Meanwhile, Mr. Trump wants to add $600 billion to the Pentagon’s annual budget, for a whopping $1.5 trillion in the next fiscal year.