Very little about public policy happens in a vacuum, least of all Hawaii’s belated move to fully implement its 15-year-old medical marijuana law, after letting things languish for so long.

When medical marijuana became legal, Hawaii was at the front of the pack among states liberalizing controls of the drug, moving first to allow its use for relief of pain and other physical symptoms. Now the long-awaited authorization of dispensaries for the delivery of marijuana to those holding a medical prescription has been overtaken by decisions in other states to legalize it entirely.

Judging by the outcome of this past legislative session — the passage of House Bill 321, an expansive effort to ramp up distribution fairly readily — it seems plain that the state is positioning itself for a full legalization debate when session reconvenes next year.

Assuming Gov. David Ige signs HB 321 into law, two things need to happen. One, lawmakers rejected the more prudently constrained startup dispensary network proposed by the Senate, so it falls to state health officials to design administrative rules that can impose sufficiently rigorous quality controls and oversight.

They have a year to accomplish that, before the dispensaries start opening July 1, 2016.

The other element is public participation in the process going forward. Public hearings on rulemaking will be part of that, but they should be focused on setting standards for medicinal dosage, which seem to be thinly defined. For manufactured products — primarily capsules, lozenges or pills containing tetrahydrocannabinol (THC), the active ingredient — each dose is restricted to 10 milligrams of THC.

But where the plant product is concerned, there seem to be inadequate standards for an appropriate dose, beyond limits of 4 ounces allowed to a qualifying purchaser in 15 days, or 8 ounces in 30 days. This is a medication, and the aim of the rulemaking should include clarifying how much THC accomplishes its aim. Expert testimony should be sought throughout this process.

The bill does call on the state Department of Health to draw on a wide range of criteria guiding the creation of the dispensary system. Licensure standards must be spelled out clearly.

Eight dispensary licenses will be issued, each one able to establish two retail dispensary locations, for a total of 16 statewide. Requirements for background checks must be made watertight.

Beyond that more immediate mission, a separate public conversation needs to begin on the next steps that will confront the state, given that the distributive infrastructure is being set in place: Should Hawaii move on to legalize, or decriminalize, marijuana?

Elected officials in the islands will have the experiences of Colorado and Washington states as guidance, and already some common assumptions are being tested.

One is that legalization is an easy route to generating state funds. Given that the black market still exists to undercut the legitimate sale of the product, tax revenue does not always meet the rosy projections. Hawaii lawmakers have to evaluate that aspect of any proposal informed by this reality.

Second, the health effects of the drug, benign or otherwise, must be weighed objectively. Now that the state is poised to establish 21 as the legal smoking age, the effects on adolescents and young adults in particular become less of a concern in the legalization debate, but the larger discussion of the medical research will be essential.

The wrangling over the medical marijuana dispensaries plan became explosive, because there is such sharp division over the broad outlines of the system. This is one reason that the issue took so many years to come to resolution.

On the one side, there’s Republican Rep. Bob McDermott, who said a smaller-scale, "boutique-style solution" would have met the need.

Others were much more sympathetic to the relief that medical marijuana can provide, easing symptoms such as pain, nausea and convulsions.

Some, such as Senate Majority Leader J. Kalani English, asserted that legalization of recreational marijuana use is the "next step for Hawaii." English said leadership would address it in the next session.

This isn’t an issue to be left for January 2016, when lawmakers return to the Capitol. State Rep. Marcus Oshiro noted, correctly, that the state has "one shot at doing the right thing the right way."

Regardless of any limitations on revenue projections, this would be a new industry, one that could leave a deep imprint through many layers of island society.

It is gratifying at least to see the state take steps to fulfill the largely empty promise of its medical marijuana law, giving patients a practical way to access the drug.

That said, the work has only just begun, with a lot more questions to be asked and answered.