Due to the delicate political situation in Arabia, Omar initially opposed military operations against the rebel tribes there, hoping to gain their support in the event of an invasion by the Romans or the Persians. Later, however, he came to agree with Abu Bakr's strategy to crush the rebellion by force. By late 632 CE, Khalid ibn Walid had successfully united Arabia after consecutive victories against the rebels. During his own reign later, Omar would mostly adopt the policy of avoiding wars and consolidating his power in the incorporated lands rather than expanding his empire through continuous warfare.