You can typically just shoot the person back, and deal with the problem that way.

Of course ýou'd want to consider the value of the target.

So let's consider a 10-story building costs $16 million to build. The enemy sends 3 20k drones out to destroy it. You counter with 6 missiles, for a total of $24 million. You've now, in a single afternoon, spent $8 million more than the building costs to rebuild.

The building obviously has utility, and might generate some income on its own, but the enemy has basically given you economic damage that is even greater than destroying the building. They spent 60k and you spent 24 million, a multiplier of 400!

Then the enemy sends 3 more drones, you're out of interceptors, and you lose the building anyway. Total cost to them: 120k. Total cost to you: $40 million. The funny thing is that by sending in 3 extra drones to destroy the building, the multiplier DROPS to 333. If they wanted to purely drain your treasury, they'd try not to destroy your buildings to motivate you to keep intercepting drones!

Wars run on money. GRRM knew exactly what he was doing when he made the Iron Bank a major political player. You need money to win wars, and even if you win the war, you may have indebted your government so much it can't recover.

One of the common themes of the fall of empires is that they own the fiat currency, therefore it is very easy for them to borrow money. So they keep borrowing money, and borrowing money, and borrowing money, until the day comes that they are spending most of their budget covering the interest.

Wars are the number one way empires run up their budgets.

The next step is the empire, losing its grip on the world, and becoming financially less stable, starts paying higher interest rates.

This is where on the map, we'd put a big arrow with the text: YOU ARE HERE (meaning the US). Bond yields are rising.

The next step is when even the interest become unaffordable, which triggers even higher rates, which cycles into higher taxes, lower services, which trigger less investment, and then it's a vicious cycle to total economic meltdown.

Nope, you've missed the point even after I've explained it.

Yes, you need to intercept that missile or drone, because it's headed towards something worth far more than the missile.

But, because the cost of a successful intercept is so high, your enemy can just keep spamming cheap ordinance at your until you run out.

In a longer war you're only delaying that point a little bit until you run out of the deluxe turbo pro interceptors you make 100 of per year.

Nope, still missing the point, still not getting it.

What the drone might have hit is irrelevant. The problem is you're spending an order of magnitude more to intercept this drone than the drone cost, meaning you will likely run out of interceptors before your enemy runs out of drones.

True, but even for a country like the USA, that becomes pretty hard to justify to your voters unless you're in a war of national survival.