"tip of the spear" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "?"
      },
      "expansion": "tip of the spear",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "_dis": "93 7",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "The foremost person or group; those on the front lines."
      ],
      "id": "en-tip_of_the_spear-en-noun-faQmbS-b",
      "links": [
        [
          "foremost",
          "foremost"
        ],
        [
          "front lines",
          "front lines"
        ]
      ]
    },
    {
      "categories": [],
      "examples": [
        {
          "ref": "2021, Trevor George Gardner, “By Any Means: A Philosophical Frame for Rulemaking Reform in Criminal Law”, in Yale Law Journal Forum, page 803",
          "text": "In this and similar theorizing of criminal-justice reform, Simonson draws the focus of reform advocates to the tip of the spear—police administration.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "The leading position of someone in a difficult situation."
      ],
      "id": "en-tip_of_the_spear-en-noun-UR7bhPZq",
      "links": [
        [
          "leading",
          "leading"
        ],
        [
          "position",
          "position"
        ]
      ]
    }
  ],
  "word": "tip of the spear"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns",
    "English nouns with unknown or uncertain plurals"
  ],
  "head_templates": [
    {
      "args": {
        "1": "?"
      },
      "expansion": "tip of the spear",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "The foremost person or group; those on the front lines."
      ],
      "links": [
        [
          "foremost",
          "foremost"
        ],
        [
          "front lines",
          "front lines"
        ]
      ]
    },
    {
      "categories": [
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "2021, Trevor George Gardner, “By Any Means: A Philosophical Frame for Rulemaking Reform in Criminal Law”, in Yale Law Journal Forum, page 803",
          "text": "In this and similar theorizing of criminal-justice reform, Simonson draws the focus of reform advocates to the tip of the spear—police administration.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "The leading position of someone in a difficult situation."
      ],
      "links": [
        [
          "leading",
          "leading"
        ],
        [
          "position",
          "position"
        ]
      ]
    }
  ],
  "word": "tip of the spear"
}