Battlecruisers or battleships for middle powers?

Were middle powers better off buying battlecruisers rather than battleships?

Only when mobility and disengagement served the mission; fixed defense against a stronger enemy generally demanded battleship protection.

Battlecruisers suit offensive raiding and situations where speed permits disengagement. They are a poor all-or-nothing investment for a smaller navy whose mission forces it to accept battle. The Ottoman battlecruiser Goeben could not use speed to escape the pre-dreadnought force guarding the exit from confined waters, and proposed Dutch battlecruisers in Southeast Asia would likewise have had to stand against a stronger Japanese force. A navy defending a fixed coastline or colony needs enough armor to survive while inflicting the damage that makes conquest unattractive. Mission and geography decide whether speed is more useful than protection.