A series of failed prosecutions for qat possession has cast doubt on whether Yemen’s favourite pastime is illegal throughout the United States.

Although qat (or "khat") is not specifically mentioned in federal drugs law, and in only a few state laws, it is regarded by police as an illicit drug. Prosecutions usually occur because of two alkaloids found in qat: cathine and cathinone

Cathine was banned by federal law in 1988, and cathinone in 1993. Local laws in many American states banned both substances in 1988, but some states took no action against qat until the federal ban on cathinone came into effect in 1993.

When making arrests for qat, police usually charge the suspect with possession of cathinone (since it is a Schedule I drug), rather than cathine, which is only Schedule III or, in some parts of the US, Schedule IV. The reason for this is that the more serious the charge, the better it looks on the arresting officer’s career record.

In fact, the amount of cathinone in qat is tiny: about 36 parts in every 100,000 when it is freshly picked. But cathinone is unstable and it rapidly degrades into cathine. Qat smuggled into the US a day or two after picking is therefore likely to contain only slight traces of cathinone.

Nevertheless, according to one lawyer, police who seize 100 pounds of qat are liable to claim that they have nabbed "100 pounds of Schedule I narcotics" - which, again, looks good on their career record.

Qat’s larger ingredient, cathine, can be found in salt form, as pseudoephedrine hydrochloride, in Sudafed, Dexatrim, and other non-prescription medicines.

Under US law, people must be given "fair notice" that a substance is illegal - which in practice means that it must appear on the banned list.

A law-abiding citizen who wanted to check the legality of qat before buying it would not find it on the federal list nor on the local list in most American states. It would also be unreasonable to expect the average person to know that qat leaves contain cathinone and cathine, two items which do appear on the lists.

In this respect, the law’s failure to mention qat is different from the way it treats other drugs of vegetable origin. For example, "marijuana" is listed in addition to its active ingredient, THC; "coca leaves" are listed in addition to cocaine.

Lack of "fair notice" has now been accepted as a defence against charges of qat possession by courts in at least six American states. One lawyer recently told Yemen Gateway that he had obtained qat 14 acquittals in a row by using this defence.

Outside Yemen and parts East Africa, where qat is widely chewed, legal attitudes vary greatly. In Britain, where qat is legal, its use is mainly confined to members of the Yemeni and Somali communities and their friends, and it has caused no social problems. Chewing is a slow, rather messy business, so it is unlikely ever to catch on as a "club culture" drug where people usually seek an instant high.

Prosecutions in the United States sometimes look more like a way of victimising ethnic minorities than maintaining law and order.

In the light of recent court rulings, the US could decide to amend its laws to include qat, by name, as a banned substance. A more sensible course would be not to tighten the law immediately but to suspend prosecutions and see if that leads to any real problems.