The government's approach to controlling opium and cocaine is very different from its approach to marijuana, tobacco, and alcohol. Opioids and cocaine, arguably, have much more serious consequences than marijuana, tobacco, and alcohol, as long-term addiction to these substances or overdose can cause death.
Marijuana, as well as various cannabis-based products, has long been lauded as an effective way to treat anxiety and pain. Alcohol use is strictly enforced for those under twenty-one in the US, and popular media is often full of warnings, both subtle and overt, about the possible impact of tobacco use.
Controlling opium and cocaine is likely much more serious to the government and international organizations because their use can have devastating health affects. To be fair, using tobacco and alcohol for long periods of time can also cause major health problems that lead to death, but the spike in opioid-related deaths in the past few years has triggered a response to a health crisis. Also, since opium often involves the use of needles (although cocaine does as well, sometimes), it contributes to the HIV/AIDS epidemic, a problem that the World Health Organization (WHO), the United Nations (UN), and various governments have waged war upon for decades.
Though cocaine and opium is often approached much more aggressively than marijuana, tobacco, and alcohol, the government has cracked down on these other substances in various ways. The minimum smoking age was recently raised to twenty-one, and many states in the US may soon ban flavored e-cigarettes. Additionally, the consequences for drunk driving or underage drinking (or both) can be quite severe.
Marijuana, however, has seen less severe control policies, with some states legalizing its use as long as it is legally produced and used for a legitimate medicinal purpose.