The Frontier of Writing

In Seamus Heaney's poem, "The Frontier of Writing," Heaney uses war imagery to convey the theme that writing is an uphill fight; a difficult process involving lengthy procedures, guidelines, and people trying to butcher your work.
The setting of the poem is stated in the first stanza - the "nilness" of the space, sorrounded by troops with guns taking your car's "make and number." All of this contributes to the dominant effect of the piece, that writing is like passing through a war-zone, everyone wants to make sure your not the "enemy," or more figuratively, that you fit to the "social norm," following the general procedure to writing that authors commonly use in the current era. This is made most evident in the line descirbing the process of analyzation of the person passing through to the "frontier of writing," in which the troops are said to be taking the "make and number" of the person, and to an extent the person behind the wheel. Typically, taking the "make and number" refers to recognizing the model/type and license plate number of a vehicle. Here, figuratively, one may think that the soldier is actually refering to the "make and number" of the person passing through, as in "where is this person coming from?" This suggests that he has to be the "right" make and number to pass through, showing that writing/editing process should conform to the social norm.
In the conclusion of the poem we find the writer passing through the frontier of writing, in which he'she feels as though passing through a waterfall, which ultimately suggests how relieving getting through the process feels. Even further, he'she feels free in the way the "open tarmac" lies in front of him/her. He/she is free to the open roads of writing.
Overall, the peom emits an effect that places the reader in the writer's position through it's vivid war imagery.