I guess we're not Portugal
".....the Portuguese decriminalization did not lead to major increases in drug use. Indeed, evidence indicates reductions in problematic use, drug-related harms and criminal justice overcrowding...."
In my discussions, it seems pretty clear there's a question about "when is it appropriate for government to act". One step I'd suggest is that when government has established a regulation which has significant negative externalities, that regulation should be abolished by the people or the government. In this case, the drug war policies have had significant negative externalities (harms to individuals, foreign policy ripples, etc) and should be abolished. In cases like our regulations and controls on contraceptives, again, negative externalities abound in STD transmission rates and rates of teens seeking abortions (teen pregnancy itself is probably a less clear negative externality and more a potential individual harm).
I have some support when there's a significant negative externality that can be averted through collective government action, say with pollution or crimes violating individuals and their property rights, or a positive externality that can be captured like with some infrastructure or with education, but there are often some flaws in the implementation. Schools for instance I'm comfortable forcing people to pay for education because of free rider problems and a significant positive externality. But not for whatever school the government says their money should go to. I'm comfortable paying for roads, but I think that controlled access roads can be built or maintained privately or paid for with congestion priced tolls to reduce pollution and congestion as the natural and undesirable outcomes of having more roads. In other words, we tax things we want, income as a method of wealth creation or jobs, and we subsidize things we don't, bad and failing school systems, corn syrup, coal and oil. This is an idiotic system of governance as a consequence. We get too much stuff we don't want (fattening foods, congested roads, gas guzzling cars spewing pollutants), and less of what we might want (income mobility, educational opportunities and innovations)
There's a lot of public choice theory problems explaining why we're getting these inefficient government policy outcomes and some proposed solutions to the problem of having to have a government in the first place that might make it a little less silly. But basically anytime it invades homes and businesses for no apparent reason and violates private property rights and private associations, it better have a damn good reason (like a warrant), and not a counter-productive one like "we're looking for consensual adults selling or producing or consuming narcotic substances".