Scotland's referendum on independence is too close to call, according to recent opinion polls. Voters in Scotland are tempted to follow their hearts on Thursday in a joyful affirmation of self-rule, and irrevocably unravel the 1707 Act of Union. If they do, they'll be making a mistake. One new poll shows 54 percent support for the "yes" vote on independence, compared with 46 percent backing for the "no" vote, excluding undecided voters. Three other weekend polls put the pro-union campaign a little ahead. The margin of error in polling means the outcome could go either way. Scotland’s Independence In a dangerous and unstable world, the ties that bind nations should not be broken without good cause. The independence campaign has failed to make the case. Granted, the pro-union campaign was worse -- slow to get started, and feeble once it did -- but those who want to overthrow the status quo, with all the costs and risks that any such constitutional revolution entails, must bear the burden of proof. The independence campaign has blithely dismissed vital questions, such as which currency the new nation would use, whether European Union membership would truly be achievable, and what Scotland's share of the U.K.'s assets and liabilities would mean for its economic outlook. It dismissed these questions because it has Bloomberg