The two-power standard watched more than Germany and America

Was the two-power standard mainly an excuse to counter Germany and the growing American overseas presence?

No; Britain watched the whole naval balance, technological change, and the scale of the foreign building response its own program would provoke.

An audience question asks whether the standard chiefly justified building against Germany and the growing American overseas presence. The answer expands the calculation to the entire world naval balance. British construction had to account for technological change and for every fleet or coalition that could threaten imperial communications. Ministers also understood that their choices would provoke foreign responses, so the issue was how large and aggressive a naval race their program would trigger.