Why was Halifax founded as a counterbalance to the French fortress at Louisbourg?

Halifax was founded in 1749 by Edward Cornwallis as a permanent British settlement and a fortified town to serve as a direct counterbalance to Louisbourg, which was a major French stronghold located on Cape Breton Island.1

Following the British takeover of Nova Scotia in 1713, the region remained a site of intense territorial struggle between Britain and France. While the British held Nova Scotia, the French maintained control of Cape Breton Island, where they heavily fortified Louisbourg to protect their interests and project power in North America. By establishing a strategic, fortified presence at the deep, ice-free harbour of Halifax, the British created a military and naval anchor to challenge French influence in the region and secure their own colonial position.1234