敘利亞政府日前宣布全面收復東古塔地區，取得一次重大的軍事勝利。但政府軍並沒有消滅該地區反對派武裝的有生力量，數萬名反政府分子只是“和平”撤退至其大本營——敘利亞西北部伊德里卜省。敘利亞政府能否並何時清除全國反叛分子，從而結束持續七年之久的歷史空前慘烈的內戰，還要打一個大大的問號。

敘利亞內戰是一場美俄深度介入的代理人戰爭，也是美俄迄今唯一直接參与並對峙的地區熱戰。敘利亞戰亂不止並呈長期化的深層原因，就在於美俄在敘利亞糾纏不休的地緣博弈。

第一，兩國代理人誰勝誰負攸關美俄重大戰略利益，雙方都志在必得。對美國來說，用軍事手段除掉薩達姆和卡扎菲後，敘利亞的巴沙爾就成了美國在阿拉伯世界唯一的“刺頭”，他是美國把敘利亞變成伊拉克、利比亞一樣的親美國家以及美國獨霸中東的主要障礙。同時，敘利亞是唯一尚存的對抗以色列的前線國家，而以色列是美國在中東戰略利益的“守護者”,美國視其為最親密的盟邦，並將以色列的安全置於與美國本土安全同等的地位。因此，美國將巴沙爾視為眼中釘，必欲除之而後快。奧巴馬政府一手扶植的敘利亞反巴武裝，是敘利亞內戰的始作俑者。美國現政府繼承前任衣缽，把推翻巴沙爾和在敘利亞實現政權更迭作為既定目標。對俄羅斯來說，敘利亞是它在中東和獨聯體以外的海外唯一勢力範圍和戰略空間，俄羅斯在敘利亞塔爾圖斯港的軍事基地是其在地中海的唯一立足點。維護親俄的巴沙爾政權對俄羅斯保障國家安全和大國地位至關重要，不容有失。倒巴與保巴是美俄對敘利亞的戰略底線，雙方都難退讓。

第二，兩家在敘利亞都付出了巨大戰略成本，都不甘半途而廢前功盡棄，因而加大了介入力度。美出錢出槍出顧問，主使敘利亞的反巴沙爾勢力打了七年內戰，多次對敘利亞政府軍進行大規模空襲，花費至巨，並曾經幫助反巴沙爾武裝攻佔了敘利亞的大部分國土，使巴沙爾政權瀕於崩潰。只是由於俄羅斯的強力介入才扭轉了敘利亞戰局，使反巴沙爾武裝遭到重創，節節敗退，政府軍“起死回生”，收復了大部分失地。但美國不甘認輸，它以“反恐”“防恐”為名，在敘利亞加大了軍事投入，增派駐軍，擴建軍事基地和安全區。目前美國在敘利亞駐軍超過2000人，它還計劃在敘利亞西北邊境部署30000人的部隊，以期在敘利亞西北部即反巴沙爾武裝的控制區建立“國中國”，作為倒巴根據地。美國還在敘利亞周邊部署強大海空軍力量，隨時準備出擊。對俄羅斯來說，參與敘利亞內戰是它在其境外最大的軍事行動，參戰部隊包括志願者在內達數萬人，投入了各類最尖端攻防武器，為扭轉敘利亞戰局付出過重大代價。俄羅斯在敘利亞軍事行動佔有道義和法律優勢，更不會輕易放棄這一有利條件，停止對敘利亞的軍事介入。為鞏固和擴大戰果，在普京連任總統後，俄羅斯進一步加強了在敘利亞的軍事力量與行動，並對美國以敘利亞政府軍使用“化學武器”為名準備對敘利亞發動新的大規模打擊威脅提出嚴厲警告。美國不甘居下風，俄羅斯要擴大戰果，雙方通過代理人的爭鬥難有窮期。

第三，美俄雙方既不願退讓，又不願迎頭相撞，博弈對峙僵局難解。圍繞巴沙爾命運的敘利亞問題有三種可能的解決前景：一是巴沙爾勝出，其政權得以維持，或巴沙爾名義上下台，敘利亞組建親俄聯合政府，即沒有巴沙爾的巴沙爾政府；二是反巴勢力勝出，由其取代巴沙爾政權，或組建親美聯合政府；三是巴沙爾下台，成立對美俄都友好的中立政府。前兩種前景分別違逆美俄戰略目標，雙方都不會接受。至於第三種前景，由於美國及其盟友的整體力量和影響相比俄羅斯占明顯優勢，所謂中立的敘利亞政府最終可能會倒向美國與西方，對此美國能接受，但俄羅斯難以接受。雙方在戰場上得不到的東西，在談判桌上也難以得到。美俄直接參与敘利亞內戰，但雙方都表示不願也竭力迴避彼此兵戎相見，因為雙方都難以承受由此帶來的嚴重後果。所以，美俄在敘利亞的對立對峙將持續下去。

第四，雙方盟友的影響。美俄不是孤家寡人，而是與其他國家或勢力組成集團參與敘利亞內戰。美國領導的集團包括歐洲盟國、沙特等海灣國家和以色列，俄羅斯領導的陣營除敘利亞以外，還有伊朗和黎巴嫩真主黨。土耳其本是美國盟國，後來倒向俄羅斯。兩大集團的成員在敘利亞有自己的利益考量，對美俄有自己的政策態度，在相關重大問題上，美俄須顧及它們的利益與政策訴求，不能完全獨斷專行。這增加了敘利亞問題解決的難度，可能拖長其戰爭進程。

解鈴還須繫鈴人。解決敘利亞問題，結束敘利亞內戰，鑰匙掌握在外部強權手中。關鍵是美俄要停止在敘利亞的地緣政治博弈，尊重敘利亞的獨立、主權和領土完整，讓敘利亞人民自己決定本國的發展道路、政治制度、政權機構。特朗普總統日前表示，美國在敘利亞的軍事行動“耗費巨大”，“一無所得”，希望儘快從敘利亞撤出美軍。果能如此，將為各方根據聯合國決議實施停火，並在聯合國主持下重開談判，尋求敘利亞問題的公平合理和平解決創造有利條件。這也是美國在敘利亞止損的明智選擇。否則，敘利亞戰亂悲劇難以止息，美國也將付出更加沉重的代價。

The Syrian government has just announced full recovery of the Eastern Ghouta area, scoring a major military success. But government troops have not eliminated all opposition forces in the region, thousands of anti-government fighters just "peacefully" withdrew to their base camp - Idrib Province in northwest Syria. Whether and when the Syrian government will be able to wipe out all rebel forces nationwide and put an end to the already 7-year civil war remains a to be seen.

The Syrian civil war is a proxy one for the US and Russia. It is at the same time the only regional hot war the two countries have participated in directly. The civil war in Syria will stretch on because of the endless geopolitical rivalry between the two countries.

First, the win or loss of their proxies is closely associated with significant US and Russian strategic interests, with both of them determined to win.For the US, after doing away with Saddam Hussein and Muammar Gaddafi, Bashar al-Assad has become its only challenger in the Arab world. By turning Syria into a pro-Washington country, the US can dominate the Middle East. Meanwhile, Syria is the only remaining frontier country to confront Israel, who is "custodian" of US strategic interests in the Middle East. Assad has thus been a thorn in the US' side. The current US administration has actually inherited the Obama administration's policy and aims to overthrow Assad and realize regime change in Syria. For Russia, Syria is its sole sphere of influence and strategic space in the Middle East and outside of the Commonwealth of Independent States, and the Russia military base at Syria's Tartous port is its only foothold in the Mediterranean Sea. Preserving the pro-Russia Assad government is critical to Russian national security and major-power status.

Both countries have invested heavily in Syria, and neither wants to give up easily.The US has been equipping and financing anti-Assad forces for seven years, carrying out large-scale air strikes on government forces, and helping opposition forces seize more than half of Syrian territory. Russia's forceful intervention has reversed the situation. But the US has increased investments in Syria, sending in more troops, and expanding bases and security zones in the name of fighting terrorism. Russia, on the other hand, would not stop military intervention in Syria considering the moral and legal advantages of its military actions in the country. Not to mention it has paid dearly in the largest military operation outside Russian territories. With neither party ready to back down, the wrangling over Syria may prove endless.

The impasse may drag on as neither wants to give in or directly confront the other.There may be three possible outcomes to the Syria crisis： one is Assad emerges victorious and he remains president, or, with Assad's nominal resignation, a pro-Russia, pro-Assad government is organized; second is anti-Assad forces emerge victorious, taking the place of the Assad government, or organizing a pro-US coalition government; third is, with the overthrow of Assad, a neutral government friendly to both the US and Russia is formed. The former two possibilities are respectively against US and Russian interests, and will hence not be acceptable. The third may be acceptable to the US but not to Russia, because a so-called neutral government may finally get closer to the US and its allies thanks to their overall strength and influence. What the two cannot get in the battlefield may not be achievable at the negotiating table either. While both directly participated in Syria's civil war, the US and Russia have tried hard to avoid confronting each other militarily, because neither can afford the subsequent cost of direct engagement. Their standoff in Syria, however, will persist.

The US and Russia did not plunge into Syria's civil war alone. The US-led camp includes European allies, Gulf countries like Saudi Arabia, and Israel; the Russia-led camp, besides Syria, includes Iran and Hezbollah. Members of both camps have their own interests in Syria. The US and Russia have to consider their allies' concerns on major policy issues, making resolution of the crisis a protracted process.

Whoever started the trouble should end it. The key to ending the civil war in Syria is in the hands of outside powers. The crux is the US and Russia should stop their geopolitical game in Syria, respect its independence, sovereignty, and territorial integrity, and let the people of Syria choose their own path of development, political system and political institutions. President Trump said recently that US military operations in Syria were costly and gained nothing for his country, and expressed the hope to withdraw as soon as possible. If that's the case, it will create favorable conditions for all parties to realize the UN-proposed truce, re-open negotiations under the auspices of the UN, and to find a fair, reasonable and peaceful solution to the crisis. This will also be a wise choice for the US to stop losses in Syria.