Many policymakers and commentators related Ukraine's fate to Taiwan's survival. They also associated failure to help Ukraine or defend Taiwan with damage to US's reputation and credibility. However, those comments were exaggerated as failure to defeat Russia in Ukraine will not have such severe global consequences for the following reasons.

The quest for marginal annexation against a US partner could ruin its military and economy.

• If Russia retained its annexed territories, it could not ignore the heavy losses to its military and economy, which the US and its allies can take credit for.
• An amphibious invasion of Taiwan is extremely difficult to execute.
• Even if China invaded successfully, Taiwan's economic infrastructure would be destroyed, making annexation of Taiwan less valuable.
• If the US and its allies decide to defend Taiwan, it will devastate the PLA and weaken the Chinese economy through sanctions.

The "Domino Theory" will not affect the US foreign policy.

• The Domino Theory from the Cold War era proposed that any countries falling into communism would spur revolutionary groups and their external sponsors, making countries fall into the communist ideology one by one.
• The US fought the costly Vietnam War to prevent communism from spreading in Vietnam and its neighboring countries but lost, and Vietnam embraced communism.
• However, the communist ideology only spread to Laos and does not affect other countries in Southeast Asia or other US-Soviet proxy wars.
• Therefore, the outcome in Ukraine will not affect the success or failure of US foreign policy.

The concepts of "Reputation" and "Credibility" are logically questionable.

• In analyzing strategic interaction, reputation has a vague role in foreign policy decisions. Although the US failed in the Vietnam War, it did not destroy US' conviction to defend Western Europe from the Soviet Union.
• Some countries may act belligerently to defend their reputation, but it is debatable whether it will draw other countries into conflict.