I think this advice is too late:
Washington could inform Tehran, Moscow and Beirut that Hezbollah should withdraw from Syria by a certain date or the United States would target any of its troops attacking non-extremist opposition forces in and around Aleppo and elsewhere. If Hezbollah failed to withdraw, the United States would then need to be ready to attack as soon as the ultimatum expired.
Hezbollah is no longer the major pillar of Assad's offensive capabilities. After so many casualties (a thousand plus dead) as the bleeding edge shock troops of Assad's attacks, I've read that Hezbollah's supporters are upset about the casualties against a non-Israel foe. So Hezbollah isn't as willing to attack for Assad. And reports that Hezbollah was manning tanks to reduce their casualties supports this.
Further, Iran's Shia foreign legion and Iranian-organized local militias are taking up more of that shock troop role.
And the Russians are far more important in sustaining offensives with logistics and fire support.
Even if Hezbollah is wiped out, Assad will continue to have offensive capabilities. So taking out Hezbollah--a relatively marginal factor--now won't affect the outcome of the civil war nearly as much as the author claims.
Also, how do we pinpoint Hezbollah targets in western Syria in face of Russian air defenses? Without spotters on the ground, we need persistent aerial surveillance to spot and track targets. Will our UAVs survive in a hostile air defense environment? Will we risk manned aircraft? Will we risk stealth F-22s to avoid Russian air defenses?
Are we really willing to risk combat with Russia for a lower tier objective that won't affect the war decisively? If we were to do this, it would have been better to do it before Russia entered the war last year.
So what do we do if Russia resists and defends Hezbollah by shooting down our recon drones and manned planes and contesting our strike aircraft?
Do we really risk war with Russia over the now-minor factor of Hezbollah support for the Assad regime when we haven't been willing to got to war to oust Assad even before Russia intervened?
No, if Hezbollah is to be struck, it should be at the end of the war--whether an Assad victory or defeat--as Hezbollah prepares to redeploy their expeditionary force from Syria back to Lebanon.