Even before the era of instant news, the words of any American president had great importance. During former president Obama’s tenure, words became a thick haze around the White House because the president spoke daily about everything that came to mind.

Now we have another president who speaks whatever comes to mind. He does it without restraint, at odd hours, usually on his Twitter account.

Since North Korea brought the current crisis to a boil, President Trump has made a great many statements and not just through his Twitter account. Some are excellent, some less so, and some are just flat wrong.

Trump has done very well by taking a tough line against North Korea’s eternal belligerence and direct threats. In the increasingly heated crisis over the Kim regime’s threats to attack America and its allies with nuclear weapons, the president threatened to respond to a North Korean attack with “…fire and fury like the world has never seen.”

Kim Jong Un, and the rest of the world, were shocked. Three American presidents — Clinton, Bush, and Obama — always responded with soothing words to which the successive Kims have each answered with even more heated belligerence. Trump’s words were necessarily tough-minded.

But two other examples of Trump’s rhetoric, unconstrained and ad-libbed, were worse than just unwise.

The first is the most recent. Addressing what he characterized (correctly) as the mess in Venezuela, the president said, “We have many options for Venezuela, including a military option if necessary.”

Venezuelan President Nicholas Maduro has extinguished the last remnants of democracy in his country left after his predecessor, Hugo Chavez, reached room temperature. We clearly have an interest in restoring Venezuelan democracy, but that interest is absolutely, positively, not a vital national security interest that could possibly justify military action.

Trump’s words reflected emotion rather than thought. If he is thinking seriously about military action in South America, he should listen to his Marines — White House chief of staff John Kelly and Defense Secretary Jim Mattis — who would tell him just how bad that idea is.

It would have been far better for the president to speak with either or both of them before saying what he did. An even worse example is what the president said about our nuclear arsenal.

In one of his remarks responding to North Korea, Trump said, “My first order as President was to renovate and modernize our nuclear arsenal. It is now far stronger and more powerful than ever before.” Each part of that statement was false. Worse still, the statement betrays an ignorance a president shouldn’t suffer.

Mr. Trump has ordered a review of our nuclear forces which should report to him in a couple of months. They haven’t been “renovated” or “modernized” yet, not by a long shot.

American nuclear forces have to be examined in terms of their parts. We have Minuteman III ICBMs in silos and Trident ICBMs in several submarines. We have nuclear capable cruise missiles. We have nuclear capable bombers, including B-52s, B-1s, and B-2s.

Though those systems are well maintained, they are aged beyond their years. The newest Minuteman IIIs (the LGM-30) became operational in 1978. The computers that control the missiles aren’t connected to the internet to prevent contamination by viruses and other malware. But those computers are from the era of the floppy disk, about thirty years ago.

Our air-launched nuclear-capable cruise missiles (AGM-68) date back to 1982.

The B-2s became operational in 1997. The last B-1s date back to 1988. The B-52H, our latest model, came into the Air Force’s inventory in 1962.

We have fourteen Ohio-class ballistic missile submarines. Each can carry twenty-four Trident missiles and each of the missiles have multiple warheads that can be individually targeted. Four other submarines have been converted to perform the same mission. The last Ohio-class boat was commissioned twenty years ago.

The last Trident missile test, conducted by U.S. and UK forces, failed in 2015 when a missile launched from a British submarine veered off course.

The nuclear forces are on different paths to retirement and modernization. As the Wall Street Journal reported, the Pentagon is about five years into a thirty-year plan to modernize the nuclear forces that will cost about $1 trillion.

Modernization has been delayed so long that it can’t be delayed any further.

Several arms control agreements have greatly reduced our nuclear arsenal. During the Cold War we had about 31,000 nuclear warheads. Now, we have about 1,400 deployed. While that arsenal may be large enough to deter our enemies, for the president to say that our arsenal is more powerful than ever is obviously wrong.

The reliability of the weapons we have hasn’t been tested in 25 years. The last underground test of a nuclear weapon was done in 1992, when President Clinton stopped the tests. Since then we have relied on computer models to test our nuclear warheads. But computer modeling has significant limitations. As the designers of the F-35 aircraft found, computer modeling doesn’t predict the actual performance of the aircraft.

We are in better shape in ballistic missile defense. But with the increasing threats from North Korea and Iran (which are working together within North Korea on ICBMs and nuclear warheads) the threat outweighs our defenses.

To defend against the long-range missile threat, we have (according to the Defense Department’s Missile Defense Agency) 36 ground-based interceptors spread between Fort Greely, Alaska and Vandenberg Air Force Base in California. The GBI system is tested very rarely because to test-fire one depletes the arsenal by at least one missile. The supply is gradually — very gradually — replaced.

On the ground, in several places around the world including South Korea, we have the Terminal High Altitude missile interceptors. Japan, for example, has both short-range Patriot anti-missile batteries and probably the THAAD system as well.

At sea, a number of Navy ships mount the Standard-3 missile defense on ships, such as Aegis cruisers, which have the massive radars to guide them. It is capable of intercepting long-range missiles such as those that Iran or North Korea could launch. The latest test, in June 2017, was conducted jointly by Japan and the US. The missile failed to intercept a target missile.

It doesn’t require a rocket scientist to conclude that our missile defenses aren’t perfectly reliable in the best of circumstances. Any enemy missiles that can’t be intercepted will hit their targets.

All of these defensive systems have one inherent weakness. Each THAAD battery, for example, is capable of launching eight defensive interceptors. But if the enemy launches nine, the system is overwhelmed.

The need to improve our ballistic missile defenses is becoming fashionable. Sen. Ted Cruz (R-TX), in a Washington Post op-ed, advocated putting ballistic missile defense systems in space. It’s a nice idea, but the costs of doing so are enormous and — thanks to congressional wrong-headedness — would be deducted from other defense expenditures. No thanks.

Even Susan Rice, Obama’s former national security advisor, said in an op-ed that we should enhance missile defenses. She also said we should “tolerate” the threat of North Korean missiles just as we do the threats of Russian and Chinese missiles. Hers is the sort of appeasement that caused the crisis we now have with North Korea.

Last week, the president said, “We are going to be increasing our budget by many billions of dollars because of North Korea, and other reasons having to do with the anti-missile…” adding that “we’ll probably be able to report that over the next week.”

But the money has to come from Congress. The president has few, if any, friends left there. His attacks on Senate Majority Leader Mitch McConnell (R-KY) were justified but — again — unwise.

Trump hasn’t had much success in getting more defense money from Congress. In his initial attempt this year, he asked for an additional $54 billion and got about half of that. It was, as I’ve written before, chump change because it wasn’t enough money even to restore the readiness of Air Force, Navy, and Marine combat aircraft.

A president’s words have great impact, regardless of the wisdom behind them. Mr. Trump’s words have reduced his political capital to near zero.

We are now in the neighborhood of war. Let’s hope the president chooses his words more carefully with the help of his closest advisors. Generals Kelly and Mattis have their work cut out for them.