Sen. Rand Paul, R-Ky., likes to present himself as a foreign policy realist. But his newly announced effort to block U.S. arms sales to Saudi Arabia is misguided liberal-idealism, not realism.

Paul says he is motivated by Saudi Arabia's possible assassination of a journalist, Jamal Khashoggi in Istanbul, Turkey, last week. Speaking to Kentucky radio station WHAL on Tuesday, Paul stated, "Believe you me, I will be forcing votes on [arms sales]. It is a point of difference with [President Trump], but who knows, the president may come around on this if there is any evidence they killed this journalist."

Don't get me wrong, I recognize why Paul's argument seems both sensible and moral at first glance. If, as appears likely, the Saudi government kidnapped or killed Khashoggi, it will have committed a blatant human rights violation and an affront to the defining American value of free speech. This situation demands the highest levels of U.S. government scrutiny.

However, it is manifestly contrary to American interests to cut arms sales to Saudi Arabia over this issue. To do so would be to bless Russia, invite worse human rights abuses, and undercut Riyadh's modernization of its society and economy. Considering that all those outcomes are antithetical to U.S. interests, ending arms sales would be the antithesis of American realism.

For a start, a suspension of U.S. arms sales would bring out the worse in Saudi political ideology. Already somewhat paranoid, the de facto Saudi leader, Crown Prince Mohammed bin Salman would likely lash out at the U.S. for interfering in his affairs. He would then receive an incredibly kind and generous phone call from Russian President Vladimir Putin: a Saudi patronage relationship is the centerpiece objective of Putin's Middle Eastern strategy. Putin would offer bin Salman his full diplomatic support at the United Nations. Putin would also offer bin Salman a subsidized deal to replace his U.S. arms purchases with Russian munitions. And Putin would also let bin Salman know that his arms sales don't come with the tedious American strings attached that the Saudi military mitigate civilian casualties in Yemen.

Meanwhile, what humanitarian or political benefits would America gain by cutting off bin Salman? I don't think there are any. Isolated from America, the young prince would have no restraint against smashing his domestic opponents and waging an Iran-style campaign against his opponents abroad. It would be bloody and relentless.

Speaking of Iran, does Rand Paul seriously think a lack of U.S. influence would encourage bin Salman to be more cautious regarding his nation's bitter enemy? Give me a break.

Paul seems motivated by delusion, and not by some blind effort to end the U.S.-Saudi alliance. Paul tweeted out on Tuesday that Saudi Arabia is the biggest state sponsor of terrorism. And that's just not true. In fact, bin Salman has the most active counter-terrorism policy of any Saudi ruler in history. (Qatar is now the leading supporter of Sunni-Salafist terrorism.) But in that same tweet Paul also referenced a November 2017 article by Daniel Lazare suggesting that it is a great mistake to believe that the Saudi regime can be modernized.

As Lazare puts it, "Wahhabism is an ideology of Bedouin zealots who may be adept at conquering their fellow tribesmen but who are incapable of governing a modern state...[T]he bottom line is an endlessly repetitive cycle in which nomadic fanatics rise up, overthrow a regime that has grown soft and corrupt, only to grow soft and corrupt themselves before succumbing to yet another wave of desert warriors. The result is anarchy piled on top of anarchy."

But Lazare gets Saudi Arabia exactly wrong. He claims that bin Salman is a Wahhabi puppet and the leader of a broken society. Wrong. For all his authoritarian impulses, bin Salman's aggressive modernization of Saudi society is designed to break the hold of the Wahhabist clergy, and to modernize the economy toward diversified growth. And let's be clear, America needs to support that effort.

The alternative is a recipe for a new ISIS at the heart of the Middle East. An unreformed Saudi Arabia will join systemic declines in oil prices to a young and jobless Saudi population, and a hard-line Sunni-Islamist theocracy. That's why Paul's Saudi Arabian realism is anything but.