The argument claims that the enforcement efforts of the authorities to prevent illegal drugs from entering the country have resulted in an increase in the illegal use of cocaine. This conclusion is based on the premise that as the authorities have become more vigilant in their efforts to prevent illegal drugs from entering the country, many drug traffickers have switched from marijuana or heroin to cocaine. The argument is based on assumptions for which there is no clear evidence. Hence, the argument is unconvincing and has several flaws.
First, the argument readily assumes that that the drug traffickers have switched from marijuana and heroin to cocaine because of an increased vigilance from the authorities. However, there is no evidence provided to support this assumption. In fact, the argument states that marijuana is bulky and heroin has a small market. Hence, it leads one to infer that due to these reasons, the drug traffickers have switched to cocaine. The argument fails to establish the correlation between an increased vigilance of authorities to the increase in the cocaine trafficking. Hence, this assumption is not valid.
Second, the argument does not provide any data regarding how successful the traffickers are in attempting to smuggle cocaine in the country. In order to access the success or failure of the authorities in diminishing the trafficking, it is necessary to analyze this information. For example, even if many traffickers have now switched to cocaine, there is no evidence that they are actually being successful in doing so. Therefore, without this crucial information, this assumption is not very sound.
Third, the argument does not present any statistics of cocaine usage before and after the increased vigilance from the authorities. The argument merely provides a weak reasoning that since many drug traffickers have switched to cocaine, there is an increase in the cocaine usage. However, there is no evidence cited to support this assumption. It is quite possible that even though there is an increase in the availability of cocaine, there is no increase in its usage. Hence, this assumption is not convincing.
In conclusion, without further evidence, the argument stands unsubstantiated and open to debate. The author must provide further evidence as stated above to make the argument more compelling.