이성계가 위화도 회군한 결정적 이유

이성계가 위화도에서 회군한 이유는 **겉으로는 ‘전쟁을 계속할 수 없는 군사·외교적 이유’였고, 실제로는 ‘고려 왕조를 뒤집고 정권을 잡기 위한 정치적 결단’**이었어요. 둘을 같이 봐야 이해가 됩니다.

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1. 당시 상황 한 번만 정리해 볼게요

• 때는 고려 말, 1388년(우왕 14년).
• 명나라가 요동(요동 정벌을 꿈꾸던 땅)을 자기 땅이라고 주장하며 철령위 설치를 선포.
• 고려 조정에서는:
• 최영: “지금이야말로 북벌(요동 정벌)해서 옛 땅 되찾자!”
• 이성계: “명은 이제 막 일어나는 초강대국인데, 지금 싸우는 건 무리다.”

결국 우왕과 최영의 강경파가 이겨서, 이성계에게 요동 정벌군 총지휘를 맡깁니다.

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2. 이성계의 ‘4불가론’ – 전쟁 못 하는 네 가지 이유

이성계는 출정을 반대하며 유명한 **‘4불가론’**을 내세웠죠. 정리하면:
1. “소국이 대국을 치는 것은 불가(小國伐大國)”
→ 신흥 강대국 명나라를, 내분 심한 고려가 이길 수 있겠냐는 현실 판단.
2. 농번기에 출정하는 것은 불가
→ 농사철에 대군을 끌고 나가면 나라 경제와 민생이 무너짐.
3. 여름 장마철 전쟁은 불가
→ 장마·전염병·보급 문제 때문에, 싸우기도 전에 군이 약해질 것.
4. 국내 정세가 불안한데 외전(外戰)은 불가
→ 고려 조정은 이미 파벌 싸움으로 혼란, 후방이 불안한 상태에서 대외전쟁은 위험.

이성계는 이 네 가지를 들어 강하게 반대했지만,
우왕·최영은 듣지 않고 억지로 출정을 밀어붙입니다.

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3. 위화도에서의 결정적 순간

요동을 향해 가던 군대는 압록강 하류의 섬, 위화도에 머물게 됩니다.

그때 이성계가 본 현실은:
• 예상대로 장마, 보급난, 전염병 위험이 현실이 되고 있었고,
• 명나라의 힘과 요동 방비도 만만치 않았고,
• 설령 싸워 이겨도, 전쟁이 길어지면 책임은 자신(이성계)에게 돌아올 것이 뻔함.

여기서 이성계 머릿속에는 두 가지가 겹칩니다.
1. 이 상태로 진격하면,
→ 나라와 군대가 함께 망하고, 실패 책임은 자기에게 뒤집어씌워질 것.
2. 지금 군권(대군 지휘권)은 자기 손에 있고,
→ 돌아가서 정권을 잡으면, 혼란한 고려를 새로 바꿀 수 있다는 계산.

그래서 이성계는 “전진” 대신 “회군(돌아감)”을 선택합니다.

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4. 왜 “위화도 회군”이 쿠데타가 되었나?

단순히 군대를 후퇴시킨 게 아니라, 방향을 뒤로 돌려 개경(수도) 으로 향했어요.
• 군대를 이끌고 개경으로 돌아와:
• 전쟁을 밀어붙이던 최영을 제거하고,
• 우왕을 폐위시키는 등 정권의 핵심을 장악합니다.
• 이 사건이 바로 위화도 회군(1388) 이고,
• 그 여파로:
• 공양왕 옹립 → 고려 왕권 무력화
• 권문세족 제거, 신흥 사대부 세력 강화
• 결국 1392년, 고려 멸망 + 조선 건국

즉, 위화도 회군은
“무리한 대외전쟁을 중단시키는 군사적 후퇴”이자
“새 왕조를 열기 위한 정치 혁명” 이었어요.

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5. 정리하면, 이성계는 왜 회군했나?

짧게 정리해 보면:
1. 명나라와의 전쟁은 승산 없는 ‘무모한 전쟁’이라고 봤고,
2. 장마·보급·국내 혼란 등 군사적으로도 실패가 뻔해 보였으며,
3. 실패했을 때 희생양이 될 자신과 군대를 지키기 위해,
4. 그 상황을 정권 교체와 새 왕조 수립의 기회로 판단했기 때문입니다.

그래서 한 줄로 말하면:

“이성계는 승산 없는 요동 정벌을 거부하고,
군권을 이용해 고려 정권을 뒤집어
새 질서를 만들기 위해 위화도에서 회군했다‘

Yi Seong-gye turned back at Wihwado because on the surface it was for military and diplomatic reasons, but in reality it was a political decision to overturn the Goryeo dynasty and seize power. You really have to see both layers together.

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1. Quick background: What was going on?

• Late Goryeo period, year 1388 (King U, 14th year).
• Ming China declared the Tieling Guard (Cheollyeongwi) and claimed control over the Liaodong region.
• In Goryeo’s court:
• Choi Yeong (Choe Yeong): “This is our chance to launch a northern campaign and reclaim our ancestral lands!”
• Yi Seong-gye: “Ming is a new rising great power. Going to war now is suicide.”

King U and Choi Yeong, the hardliners, won the argument and
appointed Yi Seong-gye as commander of the Liaodong expedition.

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2. Yi Seong-gye’s “Four Reasons Against the War” (the famous Four No’s)

Yi Seong-gye strongly opposed the campaign, presenting the well-known “Four Impossibilities (四不可論)”:
1. A small state must not attack a great power (小國伐大國 不可)
→ Realistically, weakened Goryeo could not defeat the newly rising superpower, Ming.
2. Going to war during the farming season is impossible
→ If you pull farmers away during the busy agricultural season, the entire economy and people’s livelihood collapse.
3. Waging war in the rainy summer season is impossible
→ Heavy rain, disease, and supply problems would destroy the army before it even fights.
4. With domestic politics unstable, an external war is impossible
→ The court was already torn by factional strife. Launching a foreign war with an unstable rear is extremely dangerous.

Despite these arguments,
King U and Choi Yeong ignored him and forced the expedition to go ahead.

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3. The turning point at Wihwado

On the way to Liaodong, the army stopped at Wihwado, an island in the lower Amnok (Yalu) River.

There, what Yi Seong-gye saw was:
• The reality of his concerns:
• Rainy season had begun,
• Supply and logistics were difficult,
• Disease and exhaustion were looming.
• Ming’s power and the defenses in Liaodong were formidable.
• Even if they somehow won,
if the war dragged on and failed, responsibility would fall squarely on him as commander.

So, in Yi Seong-gye’s mind, two calculations overlapped:
1. If he marched forward:
→ The country and the army could be ruined, and he would be blamed as the scapegoat.
2. At that moment, he held real military power (command of the army):
→ If he turned back and took control of the capital, he could reshape the chaotic political order.

Thus, Yi Seong-gye chose “withdrawal and return” instead of “advance.”
That choice became the Wihwado Retreat (Wihwado Hoe-gun).

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4. Why was the Wihwado Retreat effectively a coup?

It was not just a simple withdrawal. He turned the army around and marched toward Gaegyeong, the capital.

With the troops behind him, he:
• Removed Choi Yeong, who had pushed the war,
• Deposed King U, and later manipulated the royal succession,
• Took control of the core of political power.

This event is the Wihwado Retreat of 1388, and it led to:
• Establishing King Gongyang as a puppet king and weakening the Goryeo monarchy,
• Eliminating many old aristocratic elites (the gwonmun sejok),
• Strengthening the new literati and military group around Yi Seong-gye,
• Eventually, in 1392, abolishing Goryeo and founding the Joseon dynasty.

So the Wihwado Retreat was both:
• A military withdrawal to stop a reckless foreign war, and
• A political revolution that opened the path to a new dynasty.

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5. In one clear sentence: Why did Yi Seong-gye retreat?

Summing it up:
1. He believed the war with Ming was a hopeless, unwinnable campaign.
2. Military conditions (rainy season, supplies, domestic unrest) pointed clearly to disaster.
3. He needed to protect himself and his army from being sacrificed if the war failed.
4. He saw the situation as a historic opportunity to topple the failing Goryeo regime and build a new order.

So in one line:

Yi Seong-gye turned back at Wihwado to stop a suicidal war against Ming
and to use his control of the army to overturn Goryeo and establish a new dynasty (Joseon).