There are no regimes for controlling exports of munitions, much less the sale of advanced conventional weaponry, such as cluster bombs, precision-guided munitions and cruise missiles.
Despite agreements (notably the Missile Technology Control Regime) against the transfer of high technology to irresponsible countries, during the Reagan and Bush administrations countries such as Iraq, Iran and Syria were the forbidden recipients of US-made weapons. The USA administration circumvented the law with covert transfers, usually via friendly countries such as Saudi Arabia.
The key to security is not in trying to control the transfers of destructive technology and weapons as in trying to control their use. We know that two conditions for medium-term security are stable government and economic incentives. Better to some international mechanism for eliminating crackpot dictators and their syncophants; better to educate and train a target country in economic self-interest and how to further it, then to get that country economically dependent on the major trading blocs and justly fearful of ostracism from them.