2月12日，菲律賓政府向美國駐菲律賓大使館發出照會，正式決定終止美菲《訪問部隊協議》。按照協議規定，兩國可在180天內就相關問題進行磋商。由於該協議對美菲軍事同盟的重要性十分突出，這一事件走向已引發各方高度關注。

美菲軍事同盟主要依賴三個重要法律文件，即1951年《共同防禦條約》（MDT）、1998年《訪問部隊協議》（VFA）和2014年《加強防務合作協議》（EDCA）。《訪問部隊協議》在其中發揮了基礎性和承接性的關鍵作用，終止該協議將直接衝擊美國在菲律賓軍事存在的合法性，必然會對美菲軍事同盟關係造成重大現實影響。

一方面，《訪問部隊協議》是明確美軍在菲律賓地位的基礎性條約，規定了美軍人員和裝備進入菲律賓的條件、範圍和便利。實質上它是一種美國在菲律賓駐軍地位協定，只不過不是常駐而是“暫駐”。該協議中最重要的一點就是“拐彎抹角”地規定美國政府可享有對其軍事人員在菲境內犯罪行為的司法管轄權，也即通常所講的“治外法權”。這是對美國在菲律賓軍事存在權益的一種基礎性法律保障。

另一方面，《訪問部隊協議》也是明確美軍在菲律賓存在方式的承接性條約。由於菲律賓憲法禁止外國軍隊在菲領土設立軍事基地，所以《訪問部隊協議》實際上是為美軍以《共同防禦條約》為依據，借年度數百場軍事演習之名，以輪換方式派駐菲律賓大開方便之門。而《加強防務合作協議》則在此基礎上提升輪換規模，並准許美軍在菲使用和新建相關軍事設施等。所以，菲政府終止協議實為釜底抽薪，將導致《共同防禦條約》有名無實和《加強防務合作協議》名存實亡。

從目前情況來看，此事仍處於持續發酵的階段，其未來走向既有定數，也存在較大變數：

一是菲律賓政府並非心血來潮，而是經過深思熟慮。2016年杜特爾特就任菲律賓總統後，有意調整阿基諾三世政府時期對美國一邊倒的外交政策，將政策重心放回菲律賓國內經濟發展和社會穩定，不再充當美國在印太地區對華遏制戰略的“炮灰”。不選邊站隊，平衡與各方關係已成杜特爾特政府當前外交政策的鮮明特點。在此背景下，美菲外交關係熱絡、軍事演習頻密的勢頭不再。特別是在菲南部地區禁毒問題上，杜特爾特與美國齟齬不斷。本次事件的導火索也正是美方取消菲律賓前國家警察總監羅納德·德拉羅薩的赴美簽證，指責其在禁毒行動中侵犯人權。杜特爾特遂再次祭出終止《訪問部隊協議》一招，反制美方干涉菲內政的蠻橫行徑。雖然目前菲議會對總統廢約決定存在一定反對聲，但從菲媒報道情況來看，菲政府內部意見已較為統一。

二是美方恐難善罷甘休，仍將攀轅扣馬。美國防長埃斯珀表示，菲方決定是“不幸”且“方向錯誤”，美方將對此仔細研判，在未來180天內設法解決問題。這表明，一方面美國政府此前並未認真對待菲方終止協議的威脅，對菲方決定頗感意外和失措；另一方面，此舉已超出兩國軍事關係降溫的範疇，而是實質性倒退。鑒於菲律賓在美國印太戰略和中美戰略博弈中的重要地位，美方將在剩餘期限內了解菲方意圖，採取應對措施，說服或迫使菲方保留協議。

三是廢約之後何去何從，懸念猶存。耐人尋味的是，目前美菲兩國領導人仍在就此事隔空較勁，展現強硬立場，試探彼此底線。一邊是特朗普放言，“真的不在意他們（菲）那樣做，這會（讓美國）省一大筆錢”；另一邊是杜特爾特回嗆，表示終止協議“方向正確且早該如此”，“必須堅持獨立自主，不會再為維護本國利益而充當別國附庸”。應當看到，菲律賓國防實力較弱，對美國經費和訓練等軍事援助依賴較深，若協議最終廢止，如何填補防務需求缺口將是擺在杜特爾特政府面前的一大現實問題。從菲官員表態來看，目前選項有兩個。一個是與他國締結類似的軍事條約，降低對美依賴。菲軍方也承認正就此與多國進行接觸。另一個是與美方重新談判並達成更符合菲本國利益，體現菲對美戰略價值的新協議。這一點目前得到菲官員和學者較多支持。

但無論是180天內磋商還是嗣後重新談判，美菲博弈焦點將主要有三。

一是限制或取消有損菲律賓主權和利益的美軍“治外法權”，這是菲律賓民意較為集中的問題。

二是美軍事人員入境菲律賓無需辦理護照或簽證，菲方希望對等免除菲軍人員訪美簽證。

三是為菲安全提供實質性支持。菲國內有聲音認為，美方在南海爭端關鍵時刻從未真正派兵為菲方“撐場”。菲律賓想要的不是“肩並肩”的演習，而是實打實的應援。

On Feb. 12, the government of the Philippines issued a notice to the United States embassy to terminate the Visiting Forces Agreement, or VFA. Under the agreement, the two countries can negotiate issues within 180 days. The agreement is important to the U.S.-Philippine military alliance, so the development has attracted great attention around the world.

The military alliance was founded mainly on three legal documents: the 1951 Mutual Defense Treaty, the 1998 VFA and the 2014 Enhanced Defense Cooperation Agreement. The VFA is a key foundation for maintaining the U.S. military presence in the Philippines. Terminating the agreement will directly impact the legitimacy of the that presence and will inevitably have a significant practical impact on the alliance.

The VFA is a basic treaty that clarifies the status of the U.S. military in the Philippines. It lays out the conditions, scope and convenience for the temporary entry of U.S. military personnel and equipment into the country. The most important aspect of the agreement is that it explicitly provides that the U.S. government has extraterritorial jurisdiction in cases of crimes committed in the Philippines by American military personnel. It is a basic legal guarantee designed to protect the rights and interests of the United States military.

In addition, the VFA clarifies the way the U.S. handles its military presence. The Constitution of the Philippines prohibits foreign troops from establishing military bases in Philippine territory, so the VFA actually makes it possible for the U.S. military to establish a presence in rotation based on the Mutual Defense Treaty and the pretext of hundreds of military exercises each year. The EDCA increases the scale of the military presence in rotation and allows the U.S. military to use and build related military facilities.The termination of the agreement by the Philippine government will actually render the MDT and the EDCA useless.

As it stands now, the matter is escalating and will face both certainties and uncertainties in the future:

First, the Philippine government is acting not on impulse but thoughtfully. After Rodrigo Duterte assumed the presidency in 2016, he adjusted the foreign policy that leaned toward the United States and had been in place since of the administration of Benigno S. Aquino III. Duterte refocused the policy on domestic economic development and social stability to keep his country from serving as cannon fodder for the United States' strategy of containing China in the Indo-Pacific region.Balancing the relationship with all parties without siding with any particular one of them has become a distinctive feature of the current foreign policy of the Duterte government. In this context, the Philippine government is no longer as enthusiastic about U.S.-Philippine diplomatic relations and frequent military exercises as it was before.It is of particular note that on the issue of drug control in the southern Philippines, Duterte and the United States have continued to confront one another. What triggered the dispute was the U.S. revocation of former national police chief Ronald de la Rosa's visa on the grounds of his alleged violations of human rights in anti-drug operations.Duterte then retaliated with the termination of the VFA to counter the outrageous interference by the U.S. in the internal affairs of the Philippines. The Philippine parliament currently has some objections to the president's decision to scrap the treaty, but as reported in the Philippine media the official opinion of government aligns with Duterte.

Second, the United States may not let it go. U.S. Defense Secretary Mark Esper called the move by the Philippines “unfortunate” and “in the wrong direction” and that the United States would carefully study and judge this and try to solve the problem in the next 180 days. This shows that the U.S. government had not taken the threat of the Philippines scrapping the agreement seriously and was surprised and frustrated by the decision.In addition, it demonstrates that Duterte's move represented more than a cool-down in the military relations between the two countries. Rather, it was a substantial retrogression. In view of the important role of the Philippines in the U.S. Indo-Pacific strategy, as well as the Sino-U.S. strategic rivalry, the United States will strive to understand Philippine intentions during the negotiating period and take countermeasures to persuade or force it to keep the agreement going.

Third, uncertainties remain on what effects abolition of the agreement will have. It is intriguing that the leaders of the United States and the Philippines are still struggling over this issue, remaining tough and trying to test each other's bottom lines.When U.S. President Donald Trump said dismissively, “If they would like to do that, that's fine. We'll save a lot of money,” Duterte shot back with rhetoric of his own. Terminating the VFA “is a move in the right direction that should have been done a long time ago,” he said. “We must stand on our own and put a stop to being a parasite on another country in protecting our independence and sovereignty.”It should be noted that the Philippines' defense strength is weak, and the country relies heavily on U.S. military aid, including funding and training. If the agreement is ultimately abolished, how to fill the gap in the defense needs of the Philippinwes will be a major practical issue facing the Duterte government.The statements of Philippine officials suggest there are currently two options. One is to enter similar military treaties with other countries to reduce dependence on the United States. (The Philippine military has acknowledged that it is engaging with many countries in this regard.) The other is to renegotiate the deal with the United States and reach a new agreement that is more in the interest of the Philippines and reflects the strategic value of the country to the United States. This point has received more support from officials and scholars.

Whether it will be consultations within 180 days or renegotiation afterward, the focus of the U.S.-Philippine rivalry will be in three main areas:

1. Restrict or cancel the extraterritoriality of the U.S. military, which harms the sovereignty and interests of the Philippines. This is what most Filipinos think.

2. While U.S. military personnel do not need to apply for a passport or visa to enter the Philippines, the Philippine side hopes that visas for Philippine military personnel to visit the United States will be exempted.

3. Ensure that substantive support for Philippine security is provided by the United States. There is a voice in the Philippines that the United States has never sent troops in a meaningful way to support the Philippines at a critical time in the South China Sea. What the Philippines wants is not a side-by-side exercise but a practical response.