You rule Elbonia. Your military have a stockpile of 10,000 arrows, and you are paying a small village to produce 1 arrow per day, which is what you lose in regular training. This village was a planned development in the last Great War to produce 500 arrows per day at an exorbitant cost of 10,000 elbomarks a year, but peace has brough dividends; While you still fund an expensive (2,000 elbomarks/yr) retirement home in the village to keep the expertise in arrow construction literally alive, you have diversified its economy to to the point that it's actually bringing in some net tax revenue, rather than requiring an entire province worth of taxes of to hold up. The consensus is "Arrows are fucking expensive now. We could never afford to build 10 arrows per day, it would obviously break our budget".
You ask your military experts what would happen if your border region would get invaded by your rival neighbor, and they say that any scenario where the castle there holds out and breaks the siege would require upwards of 300,000 arrows to be expended in the first month, and you say "I hope my rival doesn't invade then. I'm so happy they're friendly now after the Great War." You're also happy that the regional lords under you are happy that they don't have to pay so many taxes.
Ten years in the future, the situation has changed a bit. Your neighbor is building a massive army. You say "I hope my rival doesn't invade. It doesn't look like they're close to my military yet. I'm increasing arrow production to 2 per day," at a nominal cost of 4000 elbomarks/day, but an actual cost of considerably less. You achieve this budget change... barely. Can't ask for more - can't disrupt the regional lords right now. None of them seem to think there's a threat right now.
Ten years after that, your rival is fortifying its border and building siege equipment, but your walls are high and it would need a couple more generations of larger siege tower to reach them. You hold a jousting and archery competition, and deplete your stockpiles, shooting 9000 arrows at a target in a weeklong circus of an event. This was all your idea and basically everybody criticizes you. Former supporters start talking about you retiring.
You tell the regional lords through a budget request "We're completely defenseless now. You HAVE to give me the elbomarks to rebuild the arrow-making factories and start producing 300 arrows per day, starting immediately and for the next five years, or there will definitely be war.
I'm not saying for sure how deliberately this scenario happened. It's unlikely that it failed to occur to every single advisor to Donald Trump, but whether it was part of Trump's personal decisionmaking calculus is impossible to say.