The things we can do these days.

On May 30, the Pentagon proved that a missile defense system could knock an intercontinental-range warhead out of the sky. It was like hitting a bullet with a bullet, marksmanship that could stop the North Koreans from turning Seattle into a heap of radioactive ash.

The next day, Google boasted that its machine-learning models spot spam and phishing messages with near-perfect accuracy — tossing a nearly infinite number of would-be scams into a digital Dumpster.

Take a moment to appreciate the ballistic and digital defenses that come from billions spent on Stanford and MIT graduates. Foil a missile in flight? Really tough. Sort through billions of messages with a real-life B.S. detector? That’s bananas.

Except …

In previous tests, all done in ideal conditions rather than the fog of war, the Ground-based Midcourse Defense system hit nine out of 17 dummy warheads in flight. That’s a good batting average in baseball, not so reassuring in the context of World War III.

Google said it protects your email from 99.9 percent of the garbage tossed your way. Forgive me for seeing a glass 0.1 percent empty.

For every 1,000 messages sent to seduce you with the riches of a Nigerian prince or posing as a co-worker asking you to log in on a shared work schedule, one will still get through. Given that the cost of emailing a bogus come-on is about as close to zero as you can get, the incentive to blast them out is almost endless.

What happens when it’s not your dad falling for an online grifter, but someone at the power company or the White House accidentally surrendering a user name and password to someone they shouldn’t?

Of course, we should muster our defenses. A home with a lock on the front door is safer than one without, even if burglars can bust in through a window. A country that has some success with defanging Pyonyang’s fledgling missile program is probably safer than one that throws up its hands in despair. An email account that blocks the first 999 phishing attempts beats one inundated by that spam.

Still, the imperfections of defenses remind us that good-guy technology can’t always protect us from bad-guy technology. Technology is sometimes the soft spot.

Maybe wire technology out of the equation once in a while. Two cyber analysts with The MITRE Corp., consultants to the federal government, suggest that our most critical infrastructure would be safer if it were less techy.

They note that we’ve seen fewer breaches of our physical infrastructure than of our virtual systems. That’s reason to make water plants, the electrical grid and emergency responder communications more mechanical, less electronic.

Key links in our infrastructure might best remain old school. Hold on to copper wires for critical phone calls. Stop ditching pneumatic pumps in our water systems with digital controls, MITRE’s Emily Frye and Quentin Hodgson say.

If Russians could hack into the Democratic National Committee in 2016, who’s to say the Islamic State won’t plant a virus in a dam’s digital controls in 2020?

Missile defenses and spam filters make us safer. Yet sometimes the answer is to put valuables out of reach, to make them more analog, less digital.