Germany is adamantly opposed to serving as the deep pocket for its profligate partners.
(deyim) Deep pocket is an American slang term; it usually means "extensive financial wealth or resources". It is usually used in reference to big companies or organizations (ex: the American tobacco companies have "deep pockets"), although it can be used in reference to individuals (e.g., Bill Gates, Donald Trump)
a source of substantial wealth (usually plural); "a patron of the arts should have deep pockets
a source of substantial wealth (usually plural); "a patron of the arts should have deep pockets"