I've written the following in a sentence, but now that I look at it, I'm doubting my grammatical instincts and wanted to get a second opinion.
...the balance need be swayed only slightly...
Is the use of "need be" here correct? I read this as essentially identical to:
...the balance needs to be swayed only slightly...
but I haven't been able to find any other written uses of the first syntax. Formal references for this usage would be appreciated, but more general comments are of course welcome. Thanks!