E. E. Cummings is well-known for his writing and Plato Told is typical of his individuality. It is a timeless poem which reminds the reader that war is an ongoing tragedy that will never change regardless of who is reporting on it or participating in it. The style Cummings uses can be challenging because the reader does not simply read it and move on. The reader is forced to concentrate on the unusual format and decide how it adds to Cummings' overall intention.
Internal and external deviation represent forms and accepted structures against which a poem is measured. External deviation is present here because the poem itself is different from the norm or accepted style and form not of poetry but of language in general. For example, Cummings does not capitalize any names (proper nouns) in this poem and so deviates from standard practice. Not even the first person pronoun "I" is capitalized. It may be quite common in poetry to use capitalization (or not) to suit the poet's style but it still remains a conventional feature of writing.
In terms of internal deviation, Cummings purposefully uses a unique structure as his stanzas go from one line to five lines (increasing in increments of one) and back to one line. This is internal deviation because, although poetry does usually operate in terms of stanzas, those stanzas would ordinarily have a more regular pattern and create flow whereas in this poem the format creates unexpected breaks.
The parallelism in Cummings' poem, does in fact dominate the poem. Parallelism is a literary device which relies on repetition of words or groups of words and is most evident in the repeated use of the words "told him" as the suspense in the poem builds. The similarity of the words "couldn't" and "wouldn't" also contributes to parallelism.
The unusual structure, the fast pace and the word choice all contribute to the poem and make the devastating end all the more ironic. Despite the warnings, even from the most influential figureheads, it is only a bullet to the head which started out as an inoffensive piece of metal which persuades the subject of the poem that war is futile and that there are no winners.