Benny Gantz, who quit Israel's war cabinet Sunday, is a centrist politician with dreams of toppling Prime Minister Benjamin Netanyahu's government.The former army chief and defence minister had little political experience when he launched the centre-right National Union Party in 2019 with the explicit goal of ousting Netanyahu from power.Five years later, the silver-haired Gantz is looking to ride a wave of mounting public outrage over Netanyahu's failure to return hostages held in the Gaza Strip more than eight months after the war with Hamas broke out.