<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-11-05</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0001051719</issuerCik><issuerName>UNITED DEFENSE INDUSTRIES INC</issuerName>        <issuerTradingSymbol>UDI</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001259080</rptOwnerCik><rptOwnerName>CLARE PETER J</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>C/O THE CARLYLE GROUP</rptOwnerStreet1><rptOwnerStreet2>1001 PENNSYLVANIA AVE., NW, SUITE 220S</rptOwnerStreet2><rptOwnerCity>WASHINGTON</rptOwnerCity><rptOwnerState>DC</rptOwnerState><rptOwnerZipCode>20004</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-05</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>3854.0000</value></transactionShares><transactionPricePerShare><value>33.6500</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>30146.0000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes></footnotes><remarks></remarks><ownerSignature><signatureName>Peter J. Clare</signatureName><signatureDate>2003-11-07</signatureDate></ownerSignature></ownershipDocument>

