Even risks reversing American vessel into position (4-3)

'even risks' is the definition.
(situations with uncertain outcomes)

'reversing american vessel into position' is the wordplay.
'reversing' says the letters should be written backwards.
'american vessel' becomes 'uss' (abbreviation for United States Ship).
'into' indicates putting letters inside.
'position' becomes 'spot' (synonyms).
'uss' put within 'spot' is 'spussot'.
'spussot' in reverse letter order is 'TOSS-UPS'.