The usage context is international law.

[Editing of resolutions at the United Nations][1] 

> **Structure of resolutions**
> 
> **Paragraphs**
> 
> Resolutions are essentially one long sentence. There are normally
> three elements in a resolution: the name of the organ, the preamble
> and the operative part.
> 
> - **Preambular paragraphs** are not numbered. They serve to present the background to the action part of the resolution. Preambular
> paragraphs must begin with a verb in the form of a present, past or
> perfect participle or an adjective in italics. Examples of the types
> of verbs and adjectives used in preambular paragraphs are provided in
> the annex.

See the "Annex" for lists of "Common preambular verbs and adjectives" and "Common operative verbs".


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The construction of words in law begins with the plain meaning of the words. In general, see [THE REHNQUIST COURT'S CANONS OF
STATUTORY CONSTRUCTION](http://www.ncsl.org/documents/lsss/2013pds/rehnquist_court_canons_citations.pdf).

Some of the words used in the cited document are not necessarily strictly legal terms, for example "Urges" and "Stress" are used to convey the "urging" of an action and to "stress" the point of the body which issued the resolution. "Calls upon" and "Remaining deeply concerned" are expressions used in various public settings, not only international law.

> Legal Definition of [reaffirm][2] 
>
> 1 : to affirm again 2 : to agree to
> the payment of (a dischargeable debt) with a creditor prior to the
> discharge of debts in bankruptcy

<p>

> Legal Definition of [condemn][3] 1 : to impose a penalty on; especially :
> to sentence to death 2 : to adjudge unfit for use or consumption 3 :
> to declare convertible to public use under the right of eminent domain
> : take

<p>

> Legal Definition of [express][4] : directly and distinctly stated or
> expressed rather than implied or left to inference — compare
> [implied][5]

<p>

> Definition of [stress][6] 1 : constraining force or influence: such as
> a : a force exerted when one body or body part presses on, pulls on,
> pushes against, or tends to compress or twist another body or body
> part; especially : the intensity of this mutual force commonly
> expressed in pounds per square inch b : the deformation caused in a
> body by such a force c : a physical, chemical, or emotional factor
> that causes bodily or mental tension and may be a factor in disease
> causation d : a state resulting from a stress; especially : one of
> bodily or mental tension resulting from factors that tend to alter an
> existent equilibrium job-related stress e : strain, pressure the
> environment is under stress to the point of collapse —Joseph Shoben 2
> : emphasis, weight lay stress on a point 3 archaic : intense effort or
> exertion 4 : intensity of utterance given to a speech sound, syllable,
> or word producing relative loudness 5 a : relative force or prominence
> of sound in verse b : a syllable having relative force or prominence 6
> : accent 5a

<p>

> [call upon][7]
> 
> 
> 1 : [require][8], [oblige][9] 2 : to make a demand on : depend on

<p>

> Definition of [urge][10] 
>
> urged; urging 
> transitive verb 
>
> 1 : to present,
> advocate, or demand earnestly or pressingly 2 : to undertake
> the accomplishment of with energy, swiftness, or enthusiasm 3 a : solicit, entreat b : to serve as
> a motive or reason for 4 : to force or impel
> in an indicated direction or into motion or greater speed 5 : [stimulate][11], [provoke][12]
>
> verb : to declare,
> advance, or press earnestly a statement, argument, charge, or claim

<p>

> Definition of [concerned][13] 1 a : [anxious][14], [worried][15] b :
> [interested][16]  2 a : interestedly engaged b : culpably involved


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If the question is when to use which verb or term, that is an art. 

If the question is how to write an international resolution, while style might appear to be significant, the substantive claims of the document are what matter, not the style. 

The primary requirements of any legal document are standing, jurisdiction and there being an actual live question of law.

  [1]: http://www.un.org/en/ga/second/72/editingguidelines.pdf
  [2]: https://www.merriam-webster.com/legal/reaffirm
  [3]: https://www.merriam-webster.com/dictionary/condemn#legalDictionary
  [4]: https://www.merriam-webster.com/dictionary/express#legalDictionary
  [5]: https://www.merriam-webster.com/legal/implied
  [6]: https://www.merriam-webster.com/dictionary/stress
  [7]: https://www.merriam-webster.com/dictionary/call%20on
  [8]: https://www.merriam-webster.com/dictionary/require
  [9]: https://www.merriam-webster.com/dictionary/oblige
  [10]: https://www.merriam-webster.com/dictionary/urge
  [11]: https://www.merriam-webster.com/dictionary/stimulate
  [12]: https://www.merriam-webster.com/dictionary/provoke
  [13]: https://www.merriam-webster.com/dictionary/concerned
  [14]: https://www.merriam-webster.com/dictionary/anxious
  [15]: https://www.merriam-webster.com/dictionary/worried
  [16]: https://www.merriam-webster.com/dictionary/interested