I can't say much for the attitude of the everyday man in the street, though I have just completed a dissertation on Lord Lansdowne's foreign policy so can say something for the change in foreign policy attitudes.

Prior to Lansdowne and the Boer War, Britain had relied on keeping her Empire and global interests in tact through the preponderance of British naval strength. Britain occupied a position of 'Splendid Isolation' in the world. This isolation became dangerous once the Second Boer War came about. Given the huge expenditure, it became more of a challenge for Britain to provide for the defence of India, the protection of her interests in China, Egypt, Persia etc.

During his tenure as Foreign Secretary (1900-1905), I argue in my dissertation that Lansdowne followed a policy of 'imperial consolidation', whereby he sought to curb British commitments around the world through making limited agreements with other powers in order to maintain the status quo. Britain wished to maintain the Empire, it was just too expensive to do so on her own.

The Hay-Pauncefote Treaty with the US, signed in 1901, reversed the terms of the Clayton-Bulwer Treaty (~1850s) that prevented any power from constructing an isthmian (Panama) canal. This had the effect of Britain essentially handing over supremacy of Western hemisphere waters to the US.

Additionally, the Anglo-Japanese alliance of 1902, allowed Britain to maintain the Two Power Standard (having a bigger navy than a combination of the next biggest powers) against France and Russia in the Far East and protect her interests in the Yangtze region of China against the encroachments of Russia. Indeed, Lansdowne also attempted to come to an agreement with Russia in 1903-4 prior to the outbreak of the Russo-Japanese war. The terms he sought were not too dissimilar to those secured by Sir Edward Grey in the Anglo-Russian convention of 1907; that is, the division of Persia into spheres of influence (Russia, North; Britain, South).

Also, the Anglo-French entente cordiale 1904 was an imperial agreement on African spheres of influence. Essentially what was agreed was British supremacy in East Africa, in Egypt and on the Nile, whereas the French were given compensation in West Africa (Anglo-French relations regarding Egypt had been a sore point since British occupation in 1882).

Basically, economic considerations of maintaining the Empire was a huge factor. The Boer War cost Britain £160 million a year, more than the total cost of the Crimean War and Chancellor of the Exchequer, Sir Michael Hicks-Beach, was a powerful force in the British cabinet, arguing for expenditure reforms in the navy and, in turn, a change in foreign policy attitudes. No longer could the Empire be upheld by strength; the status quo had to be maintained by striking deals and alliances with other powers.