Sarin itself has a shelf life of just a few weeks.
Keeping the precursors separate provides a shelf life of about 5 years:
Nations stockpiling sarin have tried to overcome the problem of its short shelf life in three ways. One way is to lengthen the shelf life of unitary (pure) sarin by increasing the purity of the precursor and intermediate chemicals and refining the production process. Another way to increase shelf life is by incorporating a stabilizer chemical. Initially used was tributylamine, but later this was replaced by diisopropylcarbodiimide (DIC), which allowed for sarin to be stored in aluminum casings. Finally, stockpiling of sarin can be improved by developing binary chemical weapons, where the two precursor chemicals are stored separately in the same shell, and mixed to form the agent immediately before or when the shell is in flight. This approach has the dual benefit of making the issue of shelf life irrelevant and greatly increasing the safety of sarin munitions. However, experts do not put the shelf life of this type of weapon past 5 years.
Sarin - New World Encyclopedia
The invasion of Iraq was nearly 10 years ago, people.
.
You should have donme a bit more research than Wikipedia.
I understand POLITICALLY why many wanted to claim that Bush lied...afterall, the had to explain why they were for the war before they were against it.
But to date, no one has explained how Bush got the OTHER couintries intelligence agencies to lie on his behalf.
I put in bold the pertinant parts.
EFFORTS TO LENGTHEN SHELF LIFE
IRAQ HAS TRIED TO SOLVE THIS PROBLEM IN TWO
WAYS. FIRST, IT ATTEMPTED, WITH FOREIGN
ASSISTANCE, TO IMPROVE THE SHELF-LIFE OF ITS
UNITARY SARIN BY INCREASING, THE PURITY OF
THE PRECURSOR AND INTERMEDIATE CHEMICALS
AND-REFINING PRODUCTION PROCESSES.
SECOND, IT BEGAN TO DEVELOP BINARY
CHEMICAL WEAPONS. IN A BINARY MUNITION,
THE TWO PRECURSOR CHEMICALS ARE STORED
SEPARATELY AND ONLY MIXED TO FORM THE
CHEMICAL AGENT IMMEDIATELY BEFORE OR
WHEN THE ROUND IS IN FLIGHT. THUS, THE
SHELF LIFE OF THE AGENT BECOMES IRRELEVANT;
MOREOVER, THE MUNITION IS SAFER TO HANDLE
AND STORE. BY 1990 IRAQ HAD SUCCESSFULLY
TESTED 155-MM ARTILLERY SHELLS AND OTHER
BINARY MUNITIONS AND LAUNCHED A BALLISTIC
MISSILE WITH A BINARY WARHEAD AS WELL.
CIA HOLDS THAT THE STOCKS OF SARIN MAY
REMAIN VIABLE WELL BEYOND MARCH.
CIA
ANALYSTS BELIEVE THAT THE SHELF LIFE PROBLEM
WAS ONLY TEMPORARY AND THAT THE IRAQIS
CAN NOW PRODUCE UNITARY AGENTS OF
SUFFICIENT QUALITY BY ADDING A STABILIZER OR
IMPROVING THE PRODUCTION PROCESS.
CIA ALSO BELIEVES THAT A SUBSTANTIAL
PORTION OF IRAQ'S NERVE AGENT STOCKPILE
NOW CONSISTS OF BINARY CHEMICAL WEAPONS
WHICH WOULD NOT BE SUBJECT TO
DEGRADATION.
Subject: STABILITY OF IRAQ'S CW STOCKPILE