Almost 100 states have signed a new transparency pact which obliges them to declare their ballistic missile stockpiles.
Although not legally binding, it is the most wide-ranging non-proliferation deal ever signed.
Some 93 countries, with the notable exceptions of China, Iran, India, Pakistan and Israel, signed the transparency measure at a conference in The Hague.
Each year, signatory states will declare their inventory of ballistic missiles as well as provide information on any tests they perform.
Compliance will be voluntary, because there the deal does not provide for monitoring or sanctions to ensure that states fulfil their obligations.
"There was general agreement that this international code can only be a first step on a more ambitious road," Andreas Friedrich, head of the Swiss arms control and disarmament department, told swissinfo.
He added that the agreement was still at an early stage but said signatory countries were committed to drafting implementation mechanisms over the coming year.
"This is a voluntary agreement: there is no verification mechanism but there are some rules which we are developing," Friedrich told swissinfo.
Another key aim is to clarify the precise definition of a ballistic missile. This could include anything from a scud to an Intercontinental Ballistic Missile.
"We will have to work on a definition in the coming year which will be a subject on the agenda of future talks," Friedrich said.
"Essentially, this is a symbolic gesture and it cannot resolve all the problems but it is what was possible to achieve at this time."
Switzerland does not produce or have any ballistic missiles of its own, and so the pact will have limited application here, according to the Swiss Foreign Ministry.
But Switzerland does export components that can be used in such weapons and Bern is keen to show it is actively pursuing openness in the buying and selling of such parts.
The timing of the deal is significant, coming in the same week that United Nations officials begin their mission to make an inventory of Iraq's arsenal.
swissinfo, Samantha Tonkin
93 countries have signed a transparency pact to decare their missile stockpiles
China, Iran, Israel, India and Pakistan were among those who did not sign
It is the most wide-ranging non-proliferation deal ever signed